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Flashcards in Evolution - Bk2 Deck (21)
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1
Q

What are the different TYPES of evolution?

A

Allopatric and sympatric speciation

2
Q

What are the different PATTERNS of evolution?

A

Divergent evolution, convergent evolution, co-evolution, Sequential evolution, Parallel evolution

3
Q

What is divergent evolution? what is the evidence for it?

A
  • when an ancestral species evolves into two or more species that have become specialised to occupy different ecological niches
  • homologous structures
4
Q

What are homologous structures? What is an example?

A
  • A feature seen in closely related species (e.g. had a common ancestor that is recent) that is similar in structure but used for different species
  • eg the pentadactyl limb is seen in all mammal species but used for different things (e.g. swimming, flying, walking etc.)
5
Q

What is adaptive radiation? what causes it?

A
  • When from a common ancestor, many new species evolve due to the SUDDEN availability in niche’s
  • Caused generally by a sudden die off of the species that used to occupy these niche’s
6
Q

What is convergent evolution? what is the evidence for it?

A
  • when two or more species evolve from different ancestors but develop similar features due to similar selection pressures
  • analogous structures
7
Q

What are analogous structures? what is an example of it?

A
  • a feature seen in distantly related species (e.g. had a common ancestor a long time ago) that is similar in structure and function
  • eg sharks, dolphins and penguins all have same streamlined body in order to swim fast to catch and avoid prey and predators
8
Q

Why does convergent evolution happen?

A

There are only a finite number of effective solutions to some challenges and because of this they emerge independently of each other

9
Q

What is co-evolution?

A

when 2 different species are ecologically intimate and influence each others evolution

10
Q

What are examples of types of ecologically intimate relationships? How do they influence each other?

A
  • Mutualism: evolve together to work harmoniously together
  • Parasitism: host evolves to remove it while parasite evolves to stay in/on it
  • Predator/prey: predator evolves to catch prey while it evolves to avoid it
  • Mimicry: mimicking species changes in order to match its copy species
  • Interspecific competition: evolve to avoid each other
11
Q

What is sequential evolution?

A

When the population of an entire species changes so much over time on a genetic level WITHOUT a split that organisms of each population in time would not be able to reproduce (however the old population has been replaced so is impossible to tell FYI)

12
Q

What is parallel evolution? How does it occur?

A
  • The evolution of similar anatomical or physiological features by related groups of organisms independently of each other, these features were not present in the ancestral population
  • Due to similar selection pressures in each environment
13
Q

What is a cladogram?

A

A diagram that classifies organisms according to their evolutionary relationship based on structural evidence (e.g. morphological and physiological evidence)

14
Q

What is a phylogenetic tree?

A

A diagram that classifies organisms according to their evolutionary relationship based on genetic evidence (e.g. mtDNA, amino sequence comparisons etc.)

15
Q

What are the two types of evolution rates that can occur?

A
  • punctuated equilibrium

- gradualism

16
Q

What is punctuated equilibrium?

A

It is when a species undergoes a long period of stasis (period of no evolutionary change) but then undergoes rapid speciation in a short period of time

17
Q

What causes punctuated equilibrium?

A

A period of environmental stability which is then punctuated by a short period of rapid environmental change

18
Q

How can you tell from fossil records that punctuated? Why is this?

A
  • There may be a sudden physiological change in the fossil records with no transitional species
  • the change in the physical structures of a species was so sudden and the transitional species existed for a very short time
19
Q

What is gradualism?

A

It is the slow process of divergence between different populations by the slow process of changing allele frequency and mutation

20
Q

How does gradualism occur?

A

By slowly changing selection pressures

21
Q

What types of evaluation rates do most species undergo?

A

Punctuated equilibrium