zoology - chapter two: evolution

adaptations

features that help organisms survive in their niche

DNA

nucleic acids, molecule of heredity

transitional fossils

features of two groups of organisms

fossils

what is left of extinct organisms

common ancestor

an organism whose descendants became more than one species

evolution

slow change over time, beneficial traits are passed on comm

on decent

all life shares a common ancestor

cladograms

shows the sequence of divergence based on characteristics

phylogenetic trees

show evolutionary descent of different species from a common ancestor “decent with modification”

James Hutton

“Father of modern geology” - developed gradualism (geology is not static but transforms over long periods of time), mentioned deep time

thomas Malthus

population ecologist, wrote “essay on the principal of populations”, observed that when conditions improved, populations grew, Darwin and Wallace read his writings

jean batiste Lamarck

aquired traits (do not affect DNA, not passed on to childs), contributed to evolution by proposing that organisms become more complex

charls Lyell

wrote “principals of geology”{ darwins friend, studied earthquakes and volcanoes, explained gradual change and deep time

darwins voyage of the HMS beagle

afmous for th3e findings on the galapagos and more - went to four different continents and found similar environments and animals

Alfred Russel Wallace

co discovered natural selection based on his eight year expedition to Indonesia, co published manuscript on natural selection with Darwin

charles Darwin

founder of modern day evolution, hms beagle circumnavigated the globe, “on the origin of species”, decent with modification, finches

natural selection

survival of the fittest, nature/the environment does the selecting - adaptations come from natural selection

examples of adaptations

developing pesticide resistance, camoflauge, mimicking

artificial selection

selective breeding, selection from humans

biogeography

geographic distrubution of species

homology

similarities in different species due to common ancestry

population

localized group of organisms belonging to the same species

genetic drift

change in gene frequencies from generation to generation based on chance

founder effect

individuals moving to a new location

bottleneck

population size is reduced which reduces variation

gene flow

movement of alleles from one population to another (emigration and immagration)

sexual selection

non-random mating (peacocks)

speciation

a species is a group of organisms that can reproduce and produce fertile offspring. speciation happens when members separate and develope unique charactersitcs

allopatric

type of speciation that requires a geographical barrier

sympatric

type of speciation that does not require a barrier

reproductive isolation

biological barriers that keep members of two species from interbreeding and producing viable, fertile offspring

prezygotic barrier

mating and fertilization does not occur

postzygotic barrier

mating can happen, but embryo may die or organism is sterile (mules)