Evolution and Domestication - Animal husbandry/welfare

Week 2

Define evolution

Descent with inherited modification. Biological change overtime, including both descent from common ancestors and modifications that occur within lineages.(Change over many generations)

Define Natural selection

Selection pressure from nature

Ecological niche

The role of an organism in its environment, including how the organism uses resources and interacts with other organisms.

Define inheritance

The passing of genetic information and associated traits from parents to offspring.

Define Mutation

Cause variation in alleles. May be neutral harmful or beneficial.

Define Gene flow

Is the movement of genes between populations (e.g dispersal, migration.

Define Genetic drift

Change in frequency of alleles over time due to random chance such as population isolation, or disease killing off members of a species.

• Bottleneck Effect: A sharp reduction in population size caused by a natural disaster or human activity, leaving a small, random group of survivors.

• Founder Effect: A small group splits away from the main population to establish a new colony, carrying only a fraction of the original genetic diversity

Define Artificial selection

Selection pressures from humans

What’s Darwinism Theory?

Natural Selection due to survival of the fittest- those best suited traits will survive and reproduce (Advantageous traits)

Define Homologous structure

Physical features or body parts in different species that share a common evolutionary ancestor, even if they now serve different functions

Divergent evolution

Divergent evolution is the process where two or more related species become progressively more different over time as they adapt to separate environmental pressures or niches.

Analogous structure

Different structure but perform similar functions

Convergent evolution

The independent development of similar physical traits or behaviors in unrelated or distantly related species

Biotic factors

Biotic factors include all living organisms in an environment and their interactions with one another. (Producers, consumers, decomposer etc).

Abiotic factors

Abiotic factors are the non-living environmental variables that determine where and how organisms can survive. (e.g, Light, Temp water)

Examples selection pressure

Predation, competition of resources, diseases, climate change, environmental changes, habitat modification (Human changes)

Define directional pressure + Disruptive pressure. (Type of selection pressure)

Gradual change over generations.

Maintain high frequency of two different alleles.

What’s Darwin 3 requirements for natural selection?

Pass on heritable and favourable phenotypes to offspring.

Define domestication

This is the process of a range of selection pressures on animals that ultimately make them better suited to living in close proximity to humans.

Domestication pathway - Commensal pathway

How: Animals attracted to humans/human resources. Benefits both species.

Eg. Wild cats attracted to grain stores with rodents.

Domestication pathways - Prey

How: Species initially hunted by humans e.g. sheep, cattle.

Tracking animals is time consuming so corralling some animals, restricts there movement.

Domestication pathway - Directed

How: Selecting individuals to keep in captivity/ managed settings and breed from based on desirable traits.

Why: Aim to pass on traits to next generation (Selective breeding/Artificial selection)

List some traits of domestication

Rapid growth.

Social structure.

Adaptability

Temperament

Feeding efficiency

Define domestication syndrome

A collection of physical and behavioural traits that frequently appear together in domesticated animals compared to their wild ancestors. (Reduced fear and aggression etc)

Define Co-Inheritance

The simultaneous transmission of two or more genes, alleles, or traits from parents to offspring. (That trait will influence other traits)