Evolution + Adaptations

Evolution

Process which living organisms change over time through changes in heritable traits
-relies on mutation, natural selection, selective breeding
-frequency change of alleles in population over many gens

Dawin’s theory of Evolution

Variation: in any population, individuals exhibit variations in traits

Inheritance: variations = cause by allele, pass parents → offspring

Struggle for existence: pop produce ↑ offspring than survive, → comp

Natural selection: individuals w/ advantageous traits = more likely survive + reproduce, pass traits → offspring → adaptations to selection pressures in enviro

Evolution: many generations process (natural selection) → change in population allele freq

Adaptations

Parent → offspring via genes
-enhance survival of organism in its enviro
-change over many gens, allow species adapt to their enviro

Traits of individuals allow organism = better suited to enviro (adaptation) = more common in pop over time (evolution) as pass → offspring

Tolerance range

Range of conditions (e.g. temp, rain, food + shelter availability) that organism can survive

-Generalist = survive wide range e.g rats
-Specialist = require narrow range e.g tropical fish

Structural examples

Physical features, enhance survival + reproduction in enviro
-Spikes = protection against predators
-Teeth shaped + arranged to suit to specific diet
-Colourful body = attracting mates + warn predators
-Large ears to ↑ SA + heat loss, small ears = opposite

Roo examples

Light, earth colours = camouflage
Large + sensitive ears = rotate, detect sound, locate pred + threats
Powerful hind legs = balance, hopping
Tail = balance + support when standing

Camal examples

Back hump = store fat, survive long periods w/o food
Large, flat feet = distribute weight + prevent sinking in sand
Specialised nostrils = can close nostrils, prevent sand enter nasal passage
Lashes + eyebrows – barrier against sand, sunlight
Long legs – elevate bodies above hot sand, stay cool

Physiological

Internal body processes + functions
-Vasoconstriction, dilation
-Produce concentrated urine ↓ water loss
-Produce venom 4 hunt / defence
-Cells in body coverings change colour 4 camouflage
-Mechanisms e.g shivering to generate heat
-Bioluminescence, attract mates, prey, warn preds

Bilbies example

Water Conservation
-obtaining all moisture from their diet (insects, seeds, bulbs)

Thermoregulation:
Large, hairless ears = radiators, help release excess body heat

Torpor:
enter state of dormancy, conserve energy + water in harsh condition

Behaviour

-Seeking shade / shelter avoid drastic temp change
-Active in cooler times (early morning / arvo) - ↓ water loss + heat stress
-Evaporative cooling ↓ temp (e.g. pant, lick skin + fur)
-Huddling together conserve body heat
-Migrating diff location base on feeding pattern + seasonal climate change
-Living in mobs = ↑ awareness of preds + group protection

Niche

Organisms occupy particular niche
-role in environment, interactions w/ other species + resources they use, trophic level
-2 species no occupy same niche, same time

Reproductive + Survival success

Reproductive = individual’s ability find mate + reproduce
-bright feathers, bird songs
-antlers / size, fights to win mates
-scent / colour, attract pollinators, help reproduce.

Survival = individual’s ability to survive long enough → reproductive age