evolution + adaptations Flashcards
What is variation? (2)
Refers to the differences that exist between individuals
Within a species (intraspecific) or between different species (interspecific)
What is an example of intraspecific variation? (1)
Different beak sizes in birds
What is an example of interspecific variation? (1)
Size differences between bird species
What is continuous variation? (2)
Occurs when individuals within a population vary within a range
With no distinct categories (e.g., height in humans, milk yield in animals)
What is discontinuous variation? (2)
Occurs when there are distinct categories
Each individual falls into one category (e.g., blood group in humans, seed shape in plants)
How do genetic factors cause variation? (3)
Arises from different genes and alleles
Leading to differences in genotype
Which in turn results in variation in phenotype (e.g., blood group, antibiotic resistance)
How do environmental factors cause variation? (2)
Environmental factors like climate, lifestyle, or diet
Can influence characteristics (e.g., accent, height based on nutrition)
How do both genetic and environmental factors contribute to variation? (2)
Genetics determine the potential for certain traits (e.g., height)
Environmental factors (e.g., diet) influence how those traits develop
What does standard deviation indicate in a sample? (3)
Measures the spread of values around the mean
A large SD indicates high variability\n\n- While a small SD means the values are closely grouped around the mean
What are adaptations? (2)
Features that increase an organism’s chances of survival and reproduction
Improve the chances of its offspring reproducing successfully
What are behavioural adaptations? (2)
Ways that an organism acts to increase its chance of survival
E.g., playing dead to avoid predators or engaging in courtship behaviour to increase the chances of successful mating
What are physiological adaptations? (2)
Processes inside an organism’s body that help it survive
E.g., hibernation to conserve energy in winter or bacteria producing antibiotics to reduce competition for resources
What are anatomical adaptations? (2)
Structural features of an organism’s body that enhance its survival
E.g., streamlined body shape for faster swimming or thick blubber for warmth in cold environments
What is an ecological niche? (2)
The role of an organism within its habitat
Including what it eats, when it eats, and where it feeds
Why do unrelated organisms sometimes have similar adaptations? (2)
They can develop similar adaptations when they evolve in similar environments or to fill similar ecological niches
Convergent evolution
What are the three different groups of mammals? (3)
Placental mammals (e.g., humans)
Marsupials (e.g., kangaroos)
Egg-laying monotremes (e.g., duck-billed platypus)
What are the characteristics of marsupial mammals? (2)
Have a short gestation period, do not develop a full placenta, and are born early in development
The young continue to develop in the mother’s pouch, where they attach to a teat and receive milk
What are the characteristics of placental mammals? (3)
Placental mammals have a longer gestation period and develop a placenta during pregnancy
Which allows for nutrient and waste exchange between the fetus and mother
The young are born more fully developed
How does the evolution of pesticide resistance occur in insects? (3)
Genetic mutations create alleles that confer pesticide resistance
Insects with this resistance allele survive exposure to pesticides and pass the allele to the next generation
Leading to a population with more resistant individuals
What are the implications of pesticide resistance in insects for human populations? (3)
Crop infestations become harder to control
Requiring broader pesticides that may harm beneficial insects
It could also lead to the spread of diseases like malaria if disease-carrying insects become pesticide-resistant
