Population growth and carrying capacity

What is carrying capacity (K)

The maximum number of individuals a population can support ased on available resources

what is logistic growth

when population grows quickly at first, then slows as it nears carrying capacity

What happens when a population overshoots carrying capacity

it may go above the limit temporarily, but will eventually settle back down

When is per capita growth rate closest to its maximum

when the population is small and (K - N) is large

What is the basic equation for growth rate ( r )

r = birth rate - death rate

what are density-dependent factors

factors that affect population more as density increases

What are examples of density-dependent factors

• predation

• resource limits

• waste buildup

• disease spread

• nesting site limits

• behavioral changes

What are density independent factors

factors that affect population regardless of size

what are examples of density-independent factors

• weather

• seasonal changes

• natural disasters

Which process is not a density-dependent feedback

seasonal climate change

how can sex ration affect growth rates

too few females means fewer babies

how can climate change affect sex ratio

temperature can control sex in some species (e.g warmer = more males_

what is inbreeding depression

reduced survival and reproduction in small populations due to related individuals breeding

What is species richness

the number of species in a community

what is evenness in ecology

how evenly individuals are spread across species

what makes up biodiversity

richness + evenness

what are assemblages

groups of species that tend to be found together

What are ecological roles

what species do within an community, such as prey, predator, or parasites

What are microbiomes

ecological communities of microorganisms on and in your body

Where is the biggest and most diverse microbiome

in your gut

why are microbiomes important

it helps with immunity, digestion and metabolism, mental health, defense against germs, and trains your immune system

how do we get our microbiomes

during birth, and from being outdoors and in contact with others

what reduces microbiome diversity

antibiotics, poor diet, overuse of sanitizers, lack of outdoor exposure

what are some microbiome therapies

• probiotics

• fecal transplants (pill or direct methods)

What happens in species interactions

One species increases, the other may decrease (e.g. one eats the other)

What are the main types of species interactions

• competition

• consumer-resource (predators, herbivores, parasites)

What are some specific consumer types

• predators/carnivores: eat meat

• piscivores: eat fish

• insectivores: eat insects

• herbivores: eat plants

• parasites: feed without killing immediately

What is an evolutionary arms race

one species evolves a defenses and the other evolves a counterattack, and then the whole process repeats