Evolution

1. General Evolution
Kabardino-Balkarian State University
Discipline - BIOLOGY
Lecturer: PhD
Diana Adamovna Khashkhozheva

2. From 1831 to 1836, Darwin traveled around the world on H.M.S.
Beagle, including stops in South America, Australia, and the
southern tip of Africa. Wallace traveled to Brazil to collect
insects in the Amazon rainforest from 1848 to 1852 and to the
Malay Archipelago from 1854 to 1862.

3. Charles Darwin’s Life and Work
1809-1882
English scientist
At age 21, Darwin took a job as a naturalist on the English ship HMS
Beagle which sailed to South America and the South Pacific on five-
year scientific journey around the world.
Darwin collected and studied biological specimens at every port
along the route, but focused his attention on the unique animals and
plants of the Galapagos Islands.
His studies provided the foundation for his theory of evolution by
natural selection.

4. The Five-Year Voyage of the HMS Beagle

5. The Galapagos Islands
A group of volcanic islands located off the coast
of South America
Home to a variety of unique species

6. The Unique Creatures of the Galapagos Islands

7. Darwin's Theory
1. All species that inhabit the Earth have never been created by
anyone.
2. Having arisen naturally, organic forms were slowly and
gradually transformed and improved in accordance with the
surrounding conditions.
3. The basis of the transformation of species in nature are such
properties of organisms as heredity and variability, as well as
the natural selection that is constantly occurring in nature.
4. Natural selection is carried out through the complex
interaction of organisms with each other and with the factors
of inanimate nature; it is a struggle for existence.
5. The result of evolution is the adaptation of organisms to the
conditions of their habitat and the diversity of species in
nature.

8. A rival theory, championed by the prominent biologist Jean Baptiste Lamarck, was that
evolution occurred by the inheritance of acquired characteristics. According to
Lamarck, changes that individuals acquired during their lives were passed on to their
offspring. For example, Lamarck proposed that ancestral giraffes with short necks
tended to stretch their necks to feed on tree leaves, and this extension of the neck
was passed on to subsequent generations, leading to the long-necked giraffe.

9. Fitness
• A measure of the ability to survive and produce
more offspring relative to other members of the
population in a given environment
• If differences in individual genotypes affect
fitness, then the frequencies of the genotypes
will change over generations; the genotypes with
higher fitness become more common. This
process is called natural selection.

10. The Hardy–Weinberg principle allows prediction of
genotype frequencies
The original proportions of the genotypes in a population will remain constant from generation to
generation, as long as the following assumptions are met:
1. No mutation takes place.
2. No genes are transferred to or from other sources (no immigration or emigration takes place).
3. Mating is random (individuals do not choose mates based on their phenotype or genotype).
4. The population size is very large.
5. No selection occurs.

11. Microevolution
• Observable changes in the allele frequencies of a
population over time which result in relatively
small changes within the species or population;
looks at effect of mutations and natural selection
on phenotype or form
• Examples: pesticide resistance, herbicide
resistance, bacterial resistance to antibiotics,
changes in color or size within a population

12. Macroevolution
• Evolution on a grand scale or above the level of a
population or species
• Looks at the over-arching history of life

13. Evidence for Evolution
Adaptation – any variation that aids an organism’s
chances of survival in its environment
A. Structural Adaptations
1. Mimicry – a structural adaptation that enables one
species to resemble another species
The Monarch feeds on milkweed and tastes bitter. Potential predators confuse
the Viceroy for the Monarch and avoid eating it.

14. Example 2: The colors and body shape of a yellow jacket
wasp and a harmless syrphid fly are similar. Predators
avoid both insects. The syrphid fly is on the left, and the
yellow jacket wasp is on the right.

15. 2. Camouflage – a structural adaptation that enables
species to blend with their surroundings; this usually
means that they are not easily found by their predators
and survive to reproduce
The stick insect on the left blends in almost unnoticeably
with the branch it sits on.
The mottled sand grasshopper on the right is hardly
visible on the wood.

16. B. Physiological Adaptations
1. Resistance
Involve changes in an organism’s metabolic processes
May develop in much less time than structural adaptations
Examples:
When the antibiotic drug penicillin was discovered about
50 years ago, it was called a wonder drug because it killed
many types of disease-causing bacteria and saved many
lives. Today, penicillin no longer affects as many species of
bacteria because some have evolved a physiological
adaptation to prevent being killed by penicillin.

17. Pesticides are poisons
used to kill insects that are
pests in crops, swamps,
backyards, and homes.
Examples are DDT, now
banned in many countries,
and malathion. These
chemical weapons against
insects have proved to be
double-edged swords.
Natural selection has
allowed those insects with
genes that somehow enable
them to resist the chemical
attack to survive. And their
offspring inherit the genes
for pesticide resistance.
DDT was applied
worldwide beginning in the
mid 1940’s, and by the
early 1950’s DDT would
not kill house flies.

18. C. Other Evidence for Evolution
1. Fossils – preserved remnants or impressions left by organisms that
lived in the past that help scientists to understand the overall
picture of how a species evolved; remnants of animals may be
buried, leave impressions, and/or have tissue replaced by harder
minerals

19. 2. Anatomy
a. Homologous structures – similar in origin but not in structure;
viewed as evidence that organisms evolved from a common
ancestor.

20. b. Analogous structures – similar in structure, but not in origin; do not
indicate a common evolutionary ancestor.

21. c. Vestigial structures – body structures that have no
function in present-day organisms but were probably
useful to an ancestor

22. 3. Embryology – Evolutionary biologists compare structures that
appear during the development of different organisms. All of the
different classes of vertebrates show a structures called gill slits that
appear on the side of the throat and all have a tail as an embryo. As
development continues, the differences in the embryos will increase
until you can distinguish among them. The similarities among the
young embryos suggest evolution from a distant, common ancestor.

23. 4. Biochemistry – Evolutionary relationships among species leave
signs in DNA and proteins; in genes and gene products. Scientists
compare DNA and RNA of different species and use the results of
biochemical studies to help determine the evolutionary
relationships of species. One of the most recently developed
classification systems for organisms is shown in the phylogenetic
tree below and is based on comparisons of DNA and RNA.

24. Five Agents of Evolutionary Change

25. The bottleneck effect
Even if organisms do not move
from place to place, occasionally
their populations may be
drastically reduced in size. This
may result from flooding, drought,
epidemic disease, and other
natural forces, or from changes in
the environment. The few
surviving individuals may
constitute a random genetic
sample of the original population
(unless some individuals survive
specifically because of their
genetic makeup). The resulting
alterations and loss of genetic
variability have been termed the
bottleneck effect.

26. Natural Selection
Environmental factors that keep populations in check are called selection pressures or
environmental resistances. These include: disease, competition for resources such as food and a
place in which to live, predation, lack of light, water, or oxygen, changes in temperature.

27. Stabilising selection
Stabilising selection happens
in an unchanging
environment. Extremes of the
phenotype range are selected
against, leading to a reduction
in variation (more individuals
tend to conform to the mean).
Stabilising selection occurs in
the natural selection of birth
mass in humans.

28. Directional selection
Directional selection favours one
extreme of the phenotype range
and results in a shift of the mean
either to the right or to the left.
This type of selection usually
follows some kind of
environmental change. The long
neck of the giraffe is thought to
have evolved in this way.
Probably, when food was in short
supply, only the tallest individuals
could reach enough food to
survive. They passed on their
genes to the next generation.

29. Disruptive selection
Disruptive selection selects
against intermediate phenotypes
and favours those at the
extremes. This leads to a bimodal
distribution (the distribution curve
has two peaks or modes) and two
overlapping groups of
phenotypes. If the two groups
become unable to interbreed,
then each population may give
rise to a new species.

30. PERSON AS SUBJECT TO ACTION OF EVOLUTIONARY
FACTORS
Populations numbering up to 1500 people — isolates.
Populations from 1500-4000 people are called DEMs.
DEM is the intraspecific group which is rather isolated from others similar of which it is
characteristic raised in comparison with population, panmixia degree. Unlike
population of subjects — rather short-term (there are several generations) group of
individuals. Separate Dyoma one population can differ from each other in any morpho-
physiological signs. The genetic concept Dyoma in many respects corresponds to an
ecological concept of a partsell.

31. Synthetic theory of evolution (STE) or
neo-Darwinian synthesis
Synthetic theory of evolution (also modern evolutionary
synthesis, modern synthesis or neo-Darwinian synthesis) is
a modern evolutionary theory that is a synthesis of various
disciplines, first of all, genetics and Darwinism. The
synthetic theory of evolution also relies on paleontology,
systematics, molecular biology and other disciplines.
The synthetic theory of evolution (STE)
emerged in the early 40s of the XX century. It
represents the study of evolution, developed
on the basis of data from modern genetics,
ecology and classical Darwinism. This table
presents the main provisions of the teachings
of Darwin and SHE.

32. Criteria Darwin's Evolutionary
Doctrine
STE
(neodarwinizm)
Unit of evolution species population
Evolutionary factors Hereditary variation, the
struggle for existence and
natural selection
Mutational and
combinational variability,
population waves, gene drift,
isolation, natural selection
Driving factor natural selection
The content of the concept of
"natural selection"
Survival of more adapted and
death of less adapted forms
Selective reproduction of
genotypes
Forms of natural selection Driving (sexual selection as a
kind of driving)
Directed, stabilizing,
disruptive, destabilizing
Evolution results Improving the adaptability of organisms to environmental
conditions; increasing the level of organization of living
beings; species diversity
Comparison of the theory of Darwin and Synthetic
Theory of Evolution (STE)

33. HYPOTHESES OF THE ORIGIN OF LIFE
Some ideas and hypotheses about the origin of life are widely used in different
periods of the history of the development of natural science. Currently, there are five
hypotheses of the origin of life:
1. Creationism is a hypothesis stating that life was created by a supernatural being as
a result of an act of creation, that is, God (According to the creationist hypothesis, which
has the longest history, the creation of life is an act of divine creation. Evidence of this is
the presence of special power in living organisms, " soul, "managing all life processes.
The creationism hypothesis is inspired by religious beliefs and has nothing to do with
science).
2. The hypothesis of the Stationary state, according to which life has always existed
(life never arose, but existed forever with the Earth, featuring a great variety of living
things. As the living conditions on the Earth changed, the species also changed: some
disappeared, others appeared. This hypothesis is based on mainly on the studies of
paleontology. In its essence, this hypothesis does not apply to the concepts of the origin
of life, since the question of the origin of life does not fundamentally affect).
3. Hypothesis of Spontaneous generation of life, which is based on the idea of the
repeated emergence of life from non-living matter (was put forward in ancient China
and India as an alternative to creationism.
4. Hypothesis of the historical origin of life through Biochemical evolution.

34. Hypothesis of the origin of life in the historical past as
a result of biochemical evolution (Oparin-Haldane
Theory) 1. Primitive Earth had a rarefied (i.e. oxygen-free)
atmosphere.
2. When various natural sources of energy — for
example, thunderstorms and volcanic eruptions — began to
act on this atmosphere, the basic chemical compounds
necessary for organic life began to form spontaneously.
3. Over time, molecules of organic matter accumulated in
the oceans, until they reached the consistency of hot diluted
broth. However, in some areas, the concentration of
molecules necessary for the origin of life was particularly
high, and nucleic acids and proteins were formed there.
4. Some of these molecules were capable of reproducing
themselves.
5. The interaction between nucleic acids and proteins
that have arisen eventually led to the emergence of a genetic
code.
6. Subsequently, these molecules merged, and the first
living cell appeared.
7. The first cells were heterotrophs, they could not
reproduce their components on their own and obtained them
from the broth. But over time, many compounds began to
disappear from the broth, and the cells were forced to
reproduce them independently. So the cells developed their
own metabolism for independent reproduction.
8. Due to the process of natural selection from these first
cells, all living organisms that exist on Earth appeared.

35. Human Evolution

36. Human is a biosocial creature

37. Hand Shape
Developing a more
flexible and opposed
thumb аllowed to
advanced tool use

38. Changes in brain size and skull shape
 Smaller to larger brain
capacity
 Spinal insertion moves
from rear to base of
skull
 Gradual enlargement of
the brain and facial

39. Pelvis shape
 Allowed early
hominids to
stand & walk
upright
 Gave advantage
of being able to
see around them
on the savannah

40. Spine Shape
Changed
from "C"
shape to "S"
shape

41. Jaw Size
•Jaw has reduced in size, reflecting changes in species diet
•Size of teeth have generally decreased, especially canines

42. Еvidence of human origin from
primates
1. Paleontological

43. Еvidence of human origin from primates
2. Morphological

44. Еvidence of human origin from primates
3. Genetic

45. Еvidence of human origin from
primates
4. Fetal

46. Timeline of human ancestry
~ 14-16 Million Years to (?)
- Ramapithecus &
Proconsul
 Earliest Ape-like
ancestor.
 Did not walk upright
 Similar in size to the
chimpanzee, but stockier

48. I. Australopithecus africanus
 ~ 3.5 - 1 million years -
Genus Australopithecus
 Several Species of this genus
including
 A. afarensis, A.africanus, &
A. boeisi
 Earliest is
Australopithecus
afarensis
 Very much apelike with an
important feature. Was able
to walk upright

49. II. Homo habilis, or Skillful Man
 ~ 2 - 1.5 million years
- Homo habilis
"handy man".
 Larger than
Australopithecus
 Larger brain
 Was first to use stone
tools.

50. III. Homo erectus
▪~ 1.5 Million years - ~
80,000* years . Homo
erectus.
▪Larger than H. habilis
▪Larger brain
▪Smaller face
▪Was the first to use fire
▪Allowed man to "break
out" of Africa into Europe
& Asia

51. IV. Homo neanderthalis
~130,000 - 30,000 years.
Homo neanderthalis
"Neanderthal man"
Probably not a direct
ancestor - but another
offshoot from H. erectus
Shorter, stockier, stronger
than modern man. Adapted
to ice age.
Larger brain size than
modern man.
Buried dead with flowers -
first evidence of
religeous/symbolic
thinking.

52. Cro-Magnon man
European early modern
humans (EEMH)
The Cro-Magnons ' physique was less
massive than that of the Neanderthals.
They were tall (up to 180-190 cm tall) and
had elongated body proportions.
From an evolutionary point of view, the
morphological structure and complexity of
behavior of these people differ little from
us, although the massiveness of the bones
of the skeleton and skull, the shape of
individual bones of the skeleton, etc.
anthropologists still note some differences.

53. V. “Modern” man
 ~ 100,000 years to
present - Homo
sapiens (modern
man).
 Appears to have
originated from H.
erectus in Africa, then
migrated outwards to
Europe & Asia.
 Replaced existing
species H. erectus & H.
neanderthalis

54. Evolution of organs

56. Phylogenesis of body integuments in
chordates
fish amphibians reptiles birds mammals

57. Phylogenesis of the axial skeleton of
chordates

58. Phylogenesis of the nervous system
in chordates

59. Phylogenesis of the digestive system
of chordates

60. Ontophylogenetic etiology of the
congenital defects
• skin malformations : absence of sweat glands,
ichthyosis (the process of keratinization is
disrupted, in severe cases of the disease, scales
are formed on it), hypertrichosis (excessive hair
loss), polymastia (increased the number of
mammary glands).

61. Ontophylogenetic etiology of the
congenital defects
• brain malformations: undifferentiation of
hemispheres, incomplete separation of
hemispheres of the telencephalon
(prosencephalia); ichthyopsidian («fish-brain»)
or sauropsidian («reptile-brain») types of the
brain.
• malformations of the digestive system: cervical
fistulae (rupture gill pouch), homodontous teeth,
additional lobes of the liver and pancreas,
shortening of the intestine.

62. Ontophylogenetic etiology of the
congenital defects
• Skeleton malformations: additional ribs at the 7th cervical or 1st
lumbar vertebra, splitting of posterior vertebral arches, nonunion of
spinous process of vertebrae (spina bifida), additional sacral
vertebrae; a tail.
• Skull malformations: additional bone elements, nonunion of the
hard palate (cleft palate), frontal suture; only one hearing bone;
absence of the mental prominence

63. Phylogenesis of the respiratory
system of chordates

64. Phylogenesis of the circulatory
system of chordates

65. Phylogenesis of the excretory system
of chordates

66. Ontophylogenetic etiology of
congenital defects
• Malformations of the respiratory system:
underdevelopment of the pharynx or lungs, cystic
lung hypoplasia, abnormal branching of bronchi,
hypoplasia of the diaphragm, etc.

67. Ontophylogenetic etiology of
congenital defects
• Cardiovascular malformations: ventricular septal defect, open
Botallo duct, underdevelopment of aortopulmonary septum
(incomplete separation of the arterial trunk into an aorta and
a pulmonary trunk), transposition of the great vessels,
preservation of both aortal arches, etc.

68. Ontophylogenetic etiology of
congenital defects
• Urogenital malformations: a pelvic position of kidneys,
preservation of a mesonephros, quantity abnormalities
(agenesis, aplasia, extra kidney), fusion of kidneys,
simple kidney cyst, polycystic kidney disease.

69. Good luck!