Evolution and adaptation in understanding 'animal design' Flashcards
Define phylogeny…
The pattern of evolution
“A trait that enhances fitness and that arose historically as a result of natural selection for its current biological role.”
Adaptation
What are the three requirements for something to be classed as an adaptation?
1) result in more offspring
2) be favoured by natural selection
3) not be previously used for another function
What is a key innovation and what do they lead to?
The greatest type of adaptation, leads to adaptive radiation which is an explosion of biodiversity/speciation.
Give an example of a key innovation…
When beetles started to eat flowers. Over 400,000 species of beetle! Flight is another example.
Not all traits are due to adaptations. Give 3 alternative explanations.
Phylogenetic constraint (evolution constrained due to ancestors), spandrels (neutral features), exaptation (old feature used for a new purpose).
Mediolateral vertebral column movement is primarily used by…?
Sprawling tetrapods (vertebrae)
Dorsoventral undulation is used by which vertebrates as a movement technique?
Mammals and crocodiles!
Limbs evolved from…
Fins!
Define homology…
Similarity in different species which share a common ancestor.
Speciation is…
The formation of new species
What is a vestigial structure?
A structure which an organism has but is no longer useful to it (a spandrel)
‘Movement on land’ is also known as…
Terrestrial locomotion
Define locomotion…
Expending ones own energy in order to move the centre of mass.
Is being in a lift locomotion?
No, because you are technically moving, but you are not expending your own energy to do so.
Cursorial animals have a preference for which type of locomotion?
Running!
A selective pressure is something that has an effect on…
Reproductive success
Give examples of morphological specialisations seen in cursorial animals (for endurance and speed)…
Springy, energy-efficient tendons, upright posture, elongated legs, stable trunk, large body size.
An animal’s body form and function is a product of both…
Adaptation for its environment and its phylogenetic history constraints (adaptation and ancestry).
Fusion of bones results in…
Stability and strength in that area.
New joints result in…
Increased locomotor flexibility.
Expansion of bone over time results in…
Larger area for muscle attachment.
Thickening of bone girth results in…
The ability to withstand greater loads.
