Natural selection is the process by which organisms with traits better suited to their environment tend to survive and pass on those traits, while organisms with less advantageous traits are less likely to survive and reproduce. It occurs through four main steps: 1) variation between individuals, 2) competition for limited resources, 3) survival of the fittest, and 4) reproduction of survivors. This process led giraffes to evolve from short-necked ancestors to the long-necked giraffes of today through preferential survival of longer-necked individuals over generations.
Natural selection is the gradual, non-random process by which biological traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution. The term "natural selection" was popularized by Charles Darwin who intended it to be compared with artificial selection, what we now call selective breeding.
Natural selection is a process by which beneficial traits become more common in a population over generations. It occurs through adaptation as individuals with traits that increase reproductive success are more likely to pass on those traits. There are different types of natural selection including directional selection which favors extreme phenotypes, stabilizing selection which favors intermediate phenotypes, and diversifying selection which maintains diversity in heterogeneous environments. Reproductive success and fitness are measures of how likely an individual is to contribute offspring to the next generation and natural selection acts upon traits that increase these measures.
Natural selection is the process by which heritable traits that increase an organism's chances of survival and reproduction become more common in a population over generations. Organisms with traits better suited to their environment are more likely to survive and pass on those traits, gradually changing the population over time. The peppered moth example demonstrates how a population adapted as the environment changed during the industrial revolution. Natural selection is a key driver of evolution and helps explain the diversity of life on Earth.
The document discusses pentadactyl limbs, which have five digits, in different organisms like crocodiles, penguins, echidnas, and frogs. It also discusses speciation and evidence from geographical variation, specifically focusing on the finches of Daphne Major island. The document appears to be from an IB Biology textbook covering evolution and natural selection, and discusses limb structure and function in different organisms as well as speciation patterns seen in island finches.
Natural selection is the process by which organisms with traits better suited to their environment tend to survive and pass on those traits, while organisms with less advantageous traits are less likely to survive and reproduce. It occurs through four main steps: 1) variation between individuals, 2) competition for limited resources, 3) survival of the fittest, and 4) reproduction of survivors. This process led giraffes to evolve from short-necked ancestors to the long-necked giraffes of today through preferential survival of longer-necked individuals over generations.
Natural selection is the gradual, non-random process by which biological traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution. The term "natural selection" was popularized by Charles Darwin who intended it to be compared with artificial selection, what we now call selective breeding.
Natural selection is a process by which beneficial traits become more common in a population over generations. It occurs through adaptation as individuals with traits that increase reproductive success are more likely to pass on those traits. There are different types of natural selection including directional selection which favors extreme phenotypes, stabilizing selection which favors intermediate phenotypes, and diversifying selection which maintains diversity in heterogeneous environments. Reproductive success and fitness are measures of how likely an individual is to contribute offspring to the next generation and natural selection acts upon traits that increase these measures.
Natural selection is the process by which heritable traits that increase an organism's chances of survival and reproduction become more common in a population over generations. Organisms with traits better suited to their environment are more likely to survive and pass on those traits, gradually changing the population over time. The peppered moth example demonstrates how a population adapted as the environment changed during the industrial revolution. Natural selection is a key driver of evolution and helps explain the diversity of life on Earth.
The document discusses pentadactyl limbs, which have five digits, in different organisms like crocodiles, penguins, echidnas, and frogs. It also discusses speciation and evidence from geographical variation, specifically focusing on the finches of Daphne Major island. The document appears to be from an IB Biology textbook covering evolution and natural selection, and discusses limb structure and function in different organisms as well as speciation patterns seen in island finches.
1. Austrālija
Austrālija ir tālākais kontinents, uz kuru pēc Otrā pasaules kara devās latviešu
emigranti. Salīdzinājumā ar Eiropu un Ameriku Austrālija ekonomiski bija krietni
atpalikusi, tādēļ valdība mazapdzīvotajā teritorijā labprāt integrēja svaigu
darbaspēku, solot labus darba apstākļus.
Lielāks latviešu pieplūdums Austrālijā bija pēc 1905.gada revolūcijas, kad tur meklēja
patvērumu tie, kuri bēga no soda ekspedīcijām. No 1905.gada līdz Otrajam pasaules
karam Austrālijā bija apmēram 250 - 300 latviešu. Sidnejā bija pat latviešu bibliotēka.
Bēgļus Austrālija pieņēma bez sevišķas atlases, piedāvājot noslēgt līgumu uz diviem
gadiem valsts norādītā darbā. Nometnēs līdzās latviešiem bija poļi, ungāri, ukraiņi un
citu tautu pārstāvji.
1953.gadā, kad lielākais izceļošanas vilnis beidzās, Austrālijā bija apmēram 22 000
latviešu. Galvenās bēgļu nometnes izveidojās netālu no Sidnejas un Adelaidas.
1947.gadā daži entuziasti nodibināja pirmo Austrālijas latviešu labdarības biedrību,
pēc tam Austrālijas Latviešu apvienību, kuras lielākais veikums bija Pirmo latviešu
kultūras dienu sarīkojums Sidnejā, kas kļuva par tradīciju un Austrālijas latviešu
kultūras kodolu līdzīgi dziesmu svētkiem citos kontinentos.
Visu Kultūras dienu programmā vienmēr bija kopkoru koncerti, tautas deju
sarīkojumi, teātra izrādes, tēlotājmākslas un daiļamatnieku darbu izstādes. Tomēr
katriem svētkiem bija arī kāda sava īpatnība, piemēram, plakātu izstāde ar latvisku
tematiku, fotogrāfiju un arhīva materiālu ekspozīcija, etnogrāfiski pareizāko tautas
tērpu valkāšana, dažādu speciālistu sanāksmes utt.
Adelaidā tika nodibināta Mūzikas krātuve, kas jau ar 1961.gadu centās apkopot visus
latviešu komponistu darbus, skaņuplates, notis, rokrakstus, koncertu ieskaņojumus
un citus materiālus. Šajā unikālajā krātuvē ir gandrīz 2000 skaņdarbu - no J.Cimzes
līdz mūsdienu autoru darbiem. Tagad šie materiāli atrodas Latvijā un glabājas
Nacionālās bibliotēkas Mūzikas nodaļā.
Viens no savdabīgākajiem un iespaidīgākajiem latviešiem Austrālijas mākslā ir Imants
Tillers, kas saņēmis augstus apbalvojumus pasaules lielākajās izstādēs un
domubiedrus mākslā radis visā pasaulē.
Austrālijā izveidots arī soļotāja Jāņa Daliņa fonds viņa piemiņas saglabāšanai.