Topic 1: Evolution

Question 1

Compare the two scales of evolution

Answer 1

Microevolution is evolution within a population generation to generation, over a short period of time. Macroevolution is evolution that has a phenotype change, it takes many years, and results in a new species (speciation).

Question 2

Describe Darwin’s main observations and inferences

Answer 2

Observations
1. Variability and inheritability of character traits
2. Overproduction of offspring

Inferences
1. There’s competition between offspring (because of overproduction)
2. favourable characteristics amass (become more prevalent) overtime (characteristic that’s favourable changes).

Question 3

describe the basic properties of living organisms.

Answer 3

All living organisms share several key characteristics or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing.

Question 4

explain how relationships between species are depicted in a phylogenetic tree.

Answer 4

Each branching point (point where branches split, called a node) represents the common ancestor of the species branching out from there, and their descendants. Farther away from the common ancestor, the more distantly related they are. If they share more common characteristics, and a more recent common ancestor, they are closer together on the phylogenetic tree.

Question 5

describe Darwinian fitness.

Answer 5

Relative reproductive success of an individual or genotype or the ability of an organism to pass on its alleles to the next generation.

Question 6

outline artificial selection.

Answer 6

Humans modify species by selecting and breeding individuals with desired traits. Humans artificially select for specific traits over short period of time.

Question 7

explain how natural selection can change one population into several distinct species.

Answer 7

Favourable characteristics appear more often over time and results in speciation as organisms evolve to their different environments.

Question 8

describe the evidence for relationships between species.

Answer 8

Similarities in structure (homologous structures), and molecular make up (DNA, RNA, protein sequences, and hemoglobin), of different species. Fossil record shows how structures have evolved.

Question 9

compare divergent and convergent evolution.

Answer 9

Divergent evolution: group with same ancestor, same structures diverge into different functions, (homologous). Convergent evolution: two different groups come from different ancestors but have same structure and functions, (analogous). (due to same environments adapted to).

Question 10

compare a homologous structure to an analogous structure.

Answer 10

A homologous structure has same structure and common ancestor but different functions between the species. An analogous structure has same structure and function but do NOT have common ancestor, think Away Ancestor.

Question 11

Gene

Answer 11

Unit of hereditary information consisting of specific nucleotide sequence within DNA.

Question 12

Allele

Answer 12

alternative versions of a gene that may produce varying phenotypes.

Question 13

DNA

Answer 13

genetic material capable of being replicated that determines the genetic structure of a cell’s proteins.

Question 14

Trait

Answer 14

One of two or more detectable variants in a genetic character.

Question 15

Organism

Answer 15

an individual living thing consisting of one or more cells

Question 16

Population

Answer 16

A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.

Question 17

Community

Answer 17

All the organisms that inhabit a particular area; combination of population of different species living close enough together for potential interaction.

Question 18

Ecosystem

Answer 18

All the organisms in a given area as well as the abiotic (non-living) factors with which they interact, one or more communities and the physical environment around them.

Question 19

Decent with modification

Answer 19

Characteristics present in an ancestral organism are modified in its descendants over time as they face different environments (to better fit these environments). This caused new species to diverge.

Question 20

Natural selection

Answer 20

Process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals, because of those traits.

Question 21

Divergence

Answer 21

New different species coming from same common ancestor.

Question 22

Vestigial Homologies

Answer 22

One organism has the structure, the other does too but it is not needed, just still present. Remnants of features that served a function in the organism’s ancestors.