A3 Adaptation and Evolution Review

Question 1

What is a habitat?

Answer 1

-Habitat is a place or area with a particular set of characteristics, both biotic and abiotic
-species may all live in the same habitat or not

Question 2

What is range?

Answer 2

-The geographical area where the population or species is found
-limit is usually due to habitat restrictions

Question 3

What is ecological niche?

Answer 3

-The role a species plays in a community
-what it eats, where it lives and how it interacts with other species

Question 4

What is biodiversity?

Answer 4

-Variety of species
-can vary widely depending on the biotic and abiotic components
-diversity is good

Question 5

What are factors that limit growth in ecosystems?

Answer 5

1. Abiotic limiting factors: limit the distribution and size of the populations that live there (water, soil type)
2. Biotic limiting factors: include competition, predators and parasites (interspecific is different, Intraspecific is same)

Question 6

What is natural selection?

Answer 6

-Process that results when characteristics of a population of organisms change because individuals with certain inherited traits survive and reproduce
-variety in a population must exist
-populations change not individuals

Question 7

What are selective pressures?

Answer 7

-Any reason for organisms with certain phenotypes (different observable characteristics: hair color, height) to have either a survival benefit or disadvantage

Question 8

What is evolution?

Answer 8

-Changes to a species over time
-microevolution: change to trait frequency (small change/short time)
-macroevolution: larger changes to the organism (e.g. speciation: new species is formed)

Question 9

What is Lamarck belief about evolution? (Wrong)

Answer 9

-Inheritance of acquired characteristics
-characteristics that an organism acquired during its lifetime could be passed on to their offspring
-e.g. giraffe’s long neck

Question 10

How can Darwin’s theory of evolution by natural selection be divided?

Answer 10

1. Overhead (to many babies)
2. Competition (not all survive)
3. Variation (all babies are different)
4. Survival of the fittest (some differences are good)
5. Speciation (the good ones get passed down)

Question 11

Explain “overhead” in Darwin’s theory of evolution by natural selection

Answer 11

-Number of offspring produced by a species is greater than the number that can survive, reproduce and live to maturity

Question 12

Explain “competition” in Darwin’s theory of evolution by natural selection

Answer 12

-(struggle for existence) organisms compete for limited resources such as food, water and a place to live
-competition exists between (interspecific competition) and within (Intraspecific competition) species

Question 13

Explain “variation” in Darwin’s theory of evolution by natural selection

Answer 13

-Differences in traits among members of a species are passed on to the next generation
-no two individuals are exactly alike

Question 14

Describe “survival of the fittest” in Darwin’s theory of evolution by natural selection

Answer 14

-(natural selection) species that have traits that give them an advantage are better able to compete, survive and reproduce
-this process naturally selects the organisms that survive

Question 15

Describe “speciation” in Darwin’s theory of evolution by natural selection

Answer 15

-(origin of a new species) by the inheritance of successful variations: new species arise by the accumulation of inherited variations
-eventually a new type is produced that is so different from the original that it is a new species

Question 16

What are fossil records?

Answer 16

-Fossils found in young layers of rock are much more similar to species alive today then fossils found in deeper, older layers of rock
-fossils appear in chronological order
-not all organisms appear in the fossil record at the same time

Question 17

What are transitional fossils?

Answer 17

-Fossils that show intermediary links between groups of organisms
-e.g. Archaeopteryx showed characteristics of reptiles and birds

Question 18

What is biogeography?

Answer 18

-Study of the past and present geographical distribution of organisms
-geographically close environments are more likely to be populated by related species than are locations that are geographically separate but environmentally similar

Question 19

What is anatomy?

Answer 19

-Study of the structure of organisms and their parts

Question 20

What’s are homologous structures?

Answer 20

-Those that have similar structural elements and origin but may have a different function (forelimbs of humans, frogs, bats, and dolphins)

Question 21

What are analogous structures?

Answer 21

-Those that perform similar functions even though the organisms do not have a common evolutionary origin (wing of butterfly and bat)

Question 22

What are vestigial structures?

Answer 22

-Body parts with function
-Must have served a role in some ancestor

Question 23

What is embryology?

Answer 23

-Embryos of different organisms exhibit similar stages of embryonic development

Question 24

What is molecular biology?

Answer 24

-If 2 species have similar patterns in portions of their DNA this similarity indicates that these portions of their DNA were most likely inherited from a common ancestory
-can also compare protein similarity

Question 25

What is speciation?

Answer 25

-Formation of new species - the accumulation of small changes until new member can no longer produce with original members
1. Transformation: a new species gradually replaces an old species
2. Divergence: one or more new species arise from a parent species

Question 26

What are the causes of speciation?

Answer 26

-Allopatric speciation
-sympatric speciation (more rare)

Question 27

What is allopatric speciation?

Answer 27

-(Geographic isolation): occurs when populations of a species are separated by a physical barrier

Question 28

What is sympatric speciation?

Answer 28

-Occurs without a physical barrier to mating
-mutation leading to chromosome number changes in plants

Question 29

What is adaptive radiation?

Answer 29

-When a species spreads among isolated regions (e.g. islands) and then changes as a result of different pressures