Speciation Keypounts

Question 1

Biological species concept

Answer 1

Population that has the ability to breed with one another and produce fertile offspring

Question 2

Speciation

Answer 2

Evolutionary formation of new species

Question 3

Macro evolution

Answer 3

Large scale evolutionary changes through which new species are formed over a long time period

Question 4

Repftoductive isolating mechanisms

Answer 4

Any behavioural, structural, or biochemical traits that prevent individuals of different species from reproducing successfully together

Question 5

Habitat isolation

Answer 5

Species occur in the same region, but occur different habitat so rarely encounter eachother . Example garter snakes, foujd in the same geographic locations but have different preferences, western garter inhabits moist environments, and Easter garter prefers drier areas. Different habitats isolates them and leads to reproductive isolation

Question 6

Mechanical isolation

Answer 6

Similar species are unable to Nate bc their reproductive structures are physically incompatible. In a soecies of snails, the snails can have different shell structures with different genital openings, mating can’t occur

Question 7

Temporal isolation (time)

Answer 7

Soecies with different breeding seasons. Western spotted skunks breed in fall, but the eastern species breed in late winter

Question 8

Behavioural isolation

Answer 8

Soecies have diff courtship or mating behaviours. Eastern meadowlarks and western meadowlarks, are identical in shape colouring and habitat, yet they remain seperate species bc their rituals differ, including the songs they use to attract males

Question 9

Gametic isolation

Answer 9

Sperm and egg cells of diff species are unabble to fertizlize each other. Eg sea urchins release their egg and speemcinto the surrounding water. Gametes of purple and Red Sea urchins are unable to fuse bc they have diff proteins on their egg surfaces and speed from the other species

Question 10

Hybrid inviability

Answer 10

Sometimes a hybrid dies early in development. Eg some salamander species may mate with eachother but most of the offspring don’t live to adulthood, and if they do they are weak

Question 11

Hybrid infertility

Answer 11

The hybrid of offspring mature into adults bht are infertile. Eg zonkeys (donkey and zebra ) is infertile. Mule is bred from a female horse and a male donkey. Miles are physically healthy but infertile