Mechanisms of Evolution: phylogenetic trees Flashcards Preview

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Flashcards in Mechanisms of Evolution: phylogenetic trees Deck (13)
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1

Evolution

accounts for shared characteristics across living systems/diversity: have evolved via genetic change/natural selection

2

Natural Selection occurs`

organisms in a population vary, some variation --> offspring, not all individuals survive, some variation increase probability of survival

3

Sexual selection

natural selection: mate-finding and reproductive behavior: risk factor (behaviors that attract mates attract predators)

4

Allelic/genetic drift

Random loss of alleles from (small populations); can lead to "fixation" (loss of alleles): leads to loss of diversity

5

Founder effect

Allele drift type: new populations established by a few founding individuals --> gene frequencies different from those in parent population: Lake Maracaibo + Huntington's disease --> trace back ancestry to 1 woman

6

Bottleneck effect

Allele drift type: loss of alleles as population size plunges suddenly (major environmental changes, no selective bias)

7

Allele Flow

Random movement of alleles among populations (carried by individuals)

8

Evolutionary mechanisms beyond natural selection

mutation/other variations, natural selection, allelic drift, allele flow

9

Phylogeny

study of evolutionary relationships/lineages through time

10

speciation events

branch points on phylogeny tree

11

speciation

formation of a species; population isolation + divergence contribute to: allele flow must stop

12

species

group of individuals that can interbreed in nature + produce viable/fertile offspring

13

Biological species Concept

1 Approach to defining species: distinct species do not interbreed + form fertile offspring in nature