The document details various evolutionary patterns, including convergent, divergent, and parallel evolution, along with coevolution and their implications on species adaptation and diversity. It explains how organisms change over time, leading to speciation and the emergence of analogous and homologous structures. Additionally, it distinguishes between macroevolution and microevolution, highlighting their roles in the broader context of biological diversity and adaptation.

2. Contents
Patten of Evolution
 Evolution
 Convergent Evolution
 Analogous structures
 Divergent Evolution
 Homologous structures
 Parallel Evolution
 Coevolution
 Types of Evolution
• Macroevolution
• Microevolution
 Importance of pattern of evolution

3. Evolution
“Evolution, or change over time, is the process by which modern organisms have
descended from ancient organisms. ”
 Evolution also explains how modern organisms have descended from ancient
organisms.
 Evolution is the Process by which organisms pass on traits from generation to
generation.
 Explains the origin of new species and diversity.
Change over time

4. PATTERN OF EVOLUTION
Convergent Evolution
 In evolutionary biology, convergent evolution is
the process whereby organisms not closely related
, independently evolve similar traits as a result of
having to adapt to similar environments or
ecological niches.
 Animals come from different ancestral lineages
 Caused by environmental changes
 Also called convergence
Examples
i. shark and dolphin bodies,
ii. vertebrate and cephalopod eyes
iii. the relationship between bat and insect
wings,

5. Analogous Structures
 Convergent evolution creates analogous structures that have similar form or
function but were not present in the last common ancestor of those groups.
 Organisma have the same function but not same the structure.
 Analogous structures arise from convergent evolution.

6. Divergent Evolution
 “Divergent evolution is defined as what occurs
when two groups of the same
species evolve different traits within those groups in
order to accommodate for differing environmental
and social pressures”.
 Species gradually become different from its
ancestors
 Evolution resulted in multiple different species,
leading to speciation
 Homologous structure development
 Also called adaptive radiation
 Caused by environmental changes, migration

7. Examples of Divergent Evolution
• Darwin’s Finches
Finches on the Galapagos islands
evolved into many different species to eat
different foods.
• Polar bear and brown bear
• Red fox and kit fox

8. Homologous Structue
 In divergent evolution, homologous
structures are structures indicating a species is
diverging from its ancestor.
 These structures need not have the same function as
that of those of the species' ancestors.
 Same structure
 Different function
 homologous structures arise via Divergent evolution .
 Example
 the forelimbs of humans and bats
are homologous structures.

9. Parallel Evolution
 Some species evolve without converging on similar traits
or diverging to different traits. These species undergo
change, but they maintain a constant level of similarity to
each other. This process is known as parallel evolution.
 Parallel evolution occurs when two species evolve
independently of each other, maintaining the same level
of similarity.
 Parallel evolution usually occurs between unrelated
species that do not occupy the same or similar niches in a
given habitat

10. Examples
 Marsupials and placental mammals most
recently shared common ancestor 125-
150 million years ago.yet these similar
features appeared in each of the distant
relatives

11. Parallel Evolution

12. Coevolution
 “The Process By Which Two Species Evolve In
Response To Changes In Each Other”
 Species that live in a close relationship with each
other, such as a predator-prey or symbiotic
relationship, often evolve adaptations to each
other in a process called coevolution.
Types of Coevolution
i. Parasite –host coevolution
ii. Mutualistic/Beneficial coevolution
iii. Predatory/prey coevolution

13. Examples of Coevolution
 Mutualistic/Beneficial coevolution
I. yucca moth (Tegeticula yuccasella)A female
yucca moth pushing pollen into the stigma
tube of the yucca flower while visiting the
flower to deposit her eggs.
 Predatory-prey coevolution
I. One common example is the relationship
between some species of birds and
butterflies.

14. Parasite-host coevolution
 One organism lives on other organism
harming it and possibly causing death.
 The parasite live on or in the body of the
host
 Maize plant (host) and Oospores (parasite)
 Cor/ Maize disease

15. Macroevolution
 Descent with modification
 The process by which modern organism have
descended from ancient ancestor due to many small changes
over millions years (Long time)
 macroevolution describes patterns on the tree of life at a
grand scale across vast time periods.
 Many different patterns can be observed across the tree of
life at a grand scale , including
• stability
• gradual change
• rapid change
• adaptive radiations(Divergent evolution)
• extinctions
• the co-evolution of two or more species
• convergent evolution in traits between species

16. Examples of Macroevolution
 The origin of eukaryotic life forms
 the origin of humans
 the origin of eukaryotic cells
 extinction of the dinosaurs.

17. Microevolution
 Small changes within a species’s set of genes that result in phenotypic differences
 Decades or centuries (Short time)
 Under certain environmental conditions,can produce new ,closely related
species.
 Variants in color are a form of microevolution
 Microevolution describes mechanisms that alter the frequencies of alleles in
gene pools within species
 These mechanisms include
• mutation
• Migration
• genetic drift
• natural selection

18. Examples of Microevolution
• Animals adjusting to camouflage is an example of microevolution.

19. Importance of Pattern of Evolution
 Evolution also helps in promoting biodiversity.
 It leads to speciation, it could lead to a wide range
of different organisms thriving in diverse habitats.
 Divergent evolution allows species with common
ancestral origin to be able to adapt to their own
habitats.

20. THANK you FOR LISTENING