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Lasseter AP Bio 31 Animal Behavior | You might have heard of imprinting before of organisms that they see an adult organism
right after birth and they automatically believe or take this learned experience and think
that that adult is their mother. |
Lasseter AP Bio 31 Animal Behavior | Another behavioral imprinting example is these indigo buntings that are going to migrate
at night and navigate by the stars. |
Lasseter AP Bio 31 Animal Behavior | Experiments have shown that they must know where the North Star is in order to survive
and do this migration and they have to learn this within the first few weeks of their life. |
Lasseter AP Bio 31 Animal Behavior | If they don't, they're not going to be able to follow the migration that the rest of the
birds follow. |
Lasseter AP Bio 31 Animal Behavior | It's something that is imprinted early on within the first few weeks of life. |
Lasseter AP Bio 31 Animal Behavior | It is permanent but if it's not learned, these birds are lost as far as individuals of the
species go. |
Lasseter AP Bio 31 Animal Behavior | Feedback is also very important in animal behavior. |
Lasseter AP Bio 31 Animal Behavior | Organisms respond to changes in environment through behavioral mechanisms as well as physiological
such as hibernation and migration. |
Lasseter AP Bio 31 Animal Behavior | Of course, you know bears hibernate and we'll talk about that in a second as well. |
Lasseter AP Bio 31 Animal Behavior | What is hibernation? |
Lasseter AP Bio 31 Animal Behavior | Hibernation is a relaxed state of inactivity among endotherms. |
Lasseter AP Bio 31 Animal Behavior | What happens is your metabolism and your body temperature is lowered for days or even months
and some mammals even are going to release hormones that are going to lower their metabolic
rate so we have extended torpor, an extended state of very low metabolism so it conserves
a lot of energy. |
Lasseter AP Bio 31 Animal Behavior | It's not energetically costly. |
Lasseter AP Bio 31 Animal Behavior | Bats and chipmunks are common examples of this and this is generally going to happen
seasonally within most animals that are going to hibernate and generally it's going to be
mammals or other endotherms. |
Lasseter AP Bio 31 Animal Behavior | Migration. |
Lasseter AP Bio 31 Animal Behavior | Migration is relatively long distance traveling of animals on a seasonal basis. |
Lasseter AP Bio 31 Animal Behavior | We'll see migration in all major animal groups and it's going to be caused by changes in
the external environment. |
Lasseter AP Bio 31 Animal Behavior | These could be climate changes, availability of food, season of the year, breeding purposes
but most animals that migrate do so to find food or more livable conditions and some of
course migrate to breed. |
Lasseter AP Bio 31 Animal Behavior | So our example over here is our Atlantic Salmon or Salmos Salar is the scientific name and
then when after they have a good year of growth, they are going to move to sea surface currents
and the currents are going to help carry them back to their natal river where they were
born and so they'll surf through the currents traveling thousands of kilometers and then
they're going to reach their natal river, they're going to find it by smell which is
pretty interesting so again taking those environmental cues to have them influence behavior. |
Lasseter AP Bio 31 Animal Behavior | What's interesting is only 5% of Atlantic Salmon actually go up the wrong river so 95%
of them are going to be able to be successful if they reach that part, finding their natal
river where they were born and actually end up breeding back in their original birthplace. |
Lasseter AP Bio 31 Animal Behavior | Okay let's talk about Taxus. |
Lasseter AP Bio 31 Animal Behavior | So Taxus is movement, not taxis, Taxus, movement directed toward or from a stimulus. |
Lasseter AP Bio 31 Animal Behavior | Many prokaryotes exhibit chemotaxis so we see talk about chemotaxis in bacteria which
is a change in a bacteria's movement pattern in response to chemicals but there's lots
of types of taxis so let's talk about telotaxis which is a goal directed movement. |
Lasseter AP Bio 31 Animal Behavior | It's going to describe the motion of a visual predator so you can seek a distant visual
signal and then move in the direction of that signal to attack so we have an example of
telotaxis right here. |
Lasseter AP Bio 31 Animal Behavior | There's plenty of types of taxis though but remember that taxis is not a random movement,
it's directional and it's going to be either toward or away from a stimulus but kinesis,
that is a random movement and it's going to be a random movement in response to a stimulus. |
Lasseter AP Bio 31 Animal Behavior | It's non-directional and so an example would be a movement of woodlice in relation to the
temperature around it. |
Lasseter AP Bio 31 Animal Behavior | When humidity increases the position of the woodlice is more likely to remain stationary
because they like the humidity. |
Lasseter AP Bio 31 Animal Behavior | Another similar example are the pill bugs. |
Lasseter AP Bio 31 Animal Behavior | Now you guys had some experience with these in our lab and pill bug activity is going
to increase when the environment is dry and then they're going to increase their non-random
movement, it's non-directional but they're still moving around hoping that eventually
they're going to end up in a more humid environment which the pill bugs actually prefer and then
once they're in that humid environment their activity is going to decrease but again it's
not towards or away from the dry environment, it's just non-directional. |
Lasseter AP Bio 31 Animal Behavior | Behavior can be cooperative as well. |
Lasseter AP Bio 31 Animal Behavior | Communication among individuals within a population may increase the long-term success of the
population, again a theme we're seeing here. |
Lasseter AP Bio 31 Animal Behavior | Some benefits of cooperative behavior include protection from predators, acquisition of
prey and resources, sexual reproduction, recognitions of offspring, genetic relatedness and of course
transmission of learned responses so it helps if you cooperate among different organisms
so you can transmit that to other organisms of your own species. |
Lasseter AP Bio 31 Animal Behavior | Now living systems have a variety of signal behaviors or cues that produce changes in
the behavior of other organisms and can result in differential reproductive success. |
Lasseter AP Bio 31 Animal Behavior | One example of this is territorial marking in mammals. |
Lasseter AP Bio 31 Animal Behavior | A territory is going to be a region occupied by an individual that the individual is going
to actively keep out other organisms of the same species. |
Lasseter AP Bio 31 Animal Behavior | So here we have an example of a cheetah doing some territorial marking. |
Lasseter AP Bio 31 Animal Behavior | Of course majority time this is going to be done through urination on a site, so the pheromones
are going to influence other organisms either of the same species or another species to
stay away. |
Lasseter AP Bio 31 Animal Behavior | So animals use visual, audible, tactile, electrical and chemical signals to indicate dominance
to find food, establish territory and ensure reproductive success. |
Lasseter AP Bio 31 Animal Behavior | So some examples of these are bee dances, bird songs, pack behavior in animals, herd,
flock, schooling behavior, predator warning or colony and swarming behavior in insects. |
Lasseter AP Bio 31 Animal Behavior | So let's take schooling behavior for example. |
Lasseter AP Bio 31 Animal Behavior | Fish women schools very frequently and a school has a lot of benefits because it has more
sense organs than a single individual and it can detect predators sooner and find resources
more rapidly or efficiently. |
Lasseter AP Bio 31 Animal Behavior | So those are just some of the benefits that these animals get from ensuring their reproductive
success or ensuring their success as organisms in survival. |
Lasseter AP Bio 31 Animal Behavior | Natural selection favors innate and learned behaviors that increase survival and reproductive
fitness. |
Lasseter AP Bio 31 Animal Behavior | Again going back to that natural selection we're going to see these behaviors that are
more favorable to these organisms surviving, reproducing, passing their traits onto their
offspring. |
Lasseter AP Bio 31 Animal Behavior | This is a shot from one of the original BBC planet Earth talking about birds of paradise
and their mating behaviors. |
Lasseter AP Bio 31 Animal Behavior | But some of the behaviors that have been influenced by natural selection include avoidance behaviors. |
Lasseter AP Bio 31 Animal Behavior | So organisms learn to avoid things like fences and poisons and traps. |
Lasseter AP Bio 31 Animal Behavior | It's more beneficial if they don't get caught in a trap and die and can't mate and pass
on their genes. |
Lasseter AP Bio 31 Animal Behavior | Courtship behaviors, mating behaviors and of course migration patterns all can be favored
by natural selection. |
Lasseter AP Bio 31 Animal Behavior | Okay so let's talk about some of these cooperative behaviors between different species. |
Lasseter AP Bio 31 Animal Behavior | We have niche and resource partitioning which we already talked about with the warblers. |
Lasseter AP Bio 31 Animal Behavior | These green anole lizards of the Caribbean are a little bit similar to the warblers as
well. |
Lasseter AP Bio 31 Animal Behavior | They are going to occupy again different spaces of the same tree and because they're in different
areas within the same habitat they're decreasing that competition and then thus increasing
the rate of survival of these different species within the same area. |
Lasseter AP Bio 31 Animal Behavior | Mutualism again type of symbiosis where two organisms are going to mutualistically benefit
from each other's behavior. |
Lasseter AP Bio 31 Animal Behavior | We have a gazelle I think it is here and these birds are going to eat parasites that live
on the gazelle. |
Lasseter AP Bio 31 Animal Behavior | The gazelle will benefit by the parasites being taken care of and of course the birds
get a meal which is great. |
Lasseter AP Bio 31 Animal Behavior | And of course pollination. |
Lasseter AP Bio 31 Animal Behavior | There's lots of organisms that are going to cooperate through pollination. |
Lasseter AP Bio 31 Animal Behavior | This bee here will be able to get the nectar it needs for honey production or whatever
and then the flowers of course will have the pollen trans taken away to other, excuse me
I lost my thought, the pollen taken away to other areas that it needs to pollinate. |
Lasseter AP Bio 31 Animal Behavior | Alright let's talk about activity. |
Lasseter AP Bio 31 Animal Behavior | So we have nocturnal activity and diurnal activity. |
Lasseter AP Bio 31 Animal Behavior | Now nocturnal activity of course involves animals that are active at night. |
Lasseter AP Bio 31 Animal Behavior | These are going to have highly developed senses of hearing and smell along with really developed
eyesight and they also have specialized eye cells which allow these organisms to see
better in the dark. |
Lasseter AP Bio 31 Animal Behavior | Some benefits to nocturnal activity include there's fewer predators, it's easier to ambush
prey, temperature is lower which again less energetically costly if it's not too low and
of course there's less activity which is going to allow for acute sight and hearing. |
Lasseter AP Bio 31 Animal Behavior | Diurnal activities are going to be organisms that are active during the day for the most
part so high activity during the day and resting at night. |
Lasseter AP Bio 31 Animal Behavior | And most animals in most different kingdoms are going to be diurnal. |
Lasseter AP Bio 31 Animal Behavior | In all of these groups we have a large majority of diurnal animals. |
Lasseter AP Bio 31 Animal Behavior | Let's talk about circadian rhythms. |
Lasseter AP Bio 31 Animal Behavior | So circadian rhythm is the physiological cycle of about 24 hours that is present in all eukaryotes
and persists even in the absences of external cues. |
Lasseter AP Bio 31 Animal Behavior | It can also manage larger scale activities like migration and hibernation. |
Lasseter AP Bio 31 Animal Behavior | Melatonin is going to be one of the chemicals that is an internal sleep facilitator in humans
and sometimes we actually prescribe people with melatonin as a treatment for insomnia
or the readjustment of circadian rhythms if necessary. |
Lasseter AP Bio 31 Animal Behavior | Alright I've got to finish the last ones quickly. |
Lasseter AP Bio 31 Animal Behavior | We're almost done. |
Lasseter AP Bio 31 Animal Behavior | Now jet lag is an example of circadian rhythm adjustment. |
Lasseter AP Bio 31 Animal Behavior | It's the feeling of fatigue as you move across time zones and this feeling results from the
time required to realign the circadian rhythm with the environmental cues of a new time
zone. |
Lasseter AP Bio 31 Animal Behavior | And there's actually a medical word for this. |
Lasseter AP Bio 31 Animal Behavior | We call it desynchronosis if you are having jet lag. |
Lasseter AP Bio 31 Animal Behavior | Alright finally the one thing I wanted to mention. |
Lasseter AP Bio 31 Animal Behavior | There's a great question about animal behavior and circadian rhythms on the 2015 release
biology free response question. |
Lasseter AP Bio 31 Animal Behavior | It's the one with these mice right here. |
Lasseter AP Bio 31 Animal Behavior | I recommend you check it out. |
Lasseter AP Bio 31 Animal Behavior | Do both the question, test it out on yourself and then go ahead and see the answers that
are released on the scoring guidelines. |
Lasseter AP Bio 31 Animal Behavior | Alright thanks guys. |
Lasseter AP Bio 31 Animal Behavior | Bye bye. |
video_title | transcription |
AP Biology 7.4 Population Genetics | Welcome to AP Biology. |
AP Biology 7.4 Population Genetics | I'm Gail Fizer from Darnell-Cookman Middle High School
and Florida State College in Jacksonville, Florida. |
AP Biology 7.4 Population Genetics | Today, the topic we are covering is one that colleges have asked
that all AP students study even if they will not be on the exam. |
AP Biology 7.4 Population Genetics | Colleges are supporting AP students this year
by allowing this more flexible approach to the exam. |
AP Biology 7.4 Population Genetics | It will focus on a lesser amount of content than in other years. |
AP Biology 7.4 Population Genetics | But in turn, they have asked that AP students learn today's material. |
AP Biology 7.4 Population Genetics | To make this relevant to your upcoming exam,
we'll also include some exam prep in today's lesson. |
AP Biology 7.4 Population Genetics | Soon after we've covered some of these key outstanding topics,
we'll be posting the full schedule of review topics for the remainder of this course
so that you can choose which topic you want,
which topics you want to prioritize for review,
and thus which classes you'll want to attend. |
AP Biology 7.4 Population Genetics | Now for an overview of our lesson. |
AP Biology 7.4 Population Genetics | So today, we're going to be talking about topic 7.4, which is population genetics. |
AP Biology 7.4 Population Genetics | I'll be introducing you to population genetics,
science practice skill 3B, which is questions and methods. |
AP Biology 7.4 Population Genetics | And we're going to be stating the null or alternative hypotheses
and predicting the results of an experiment. |
AP Biology 7.4 Population Genetics | You should already be familiar with the causes of natural selection,
how natural selection affects populations,
the importance of phenotypic variation in a population,
and explaining biological concepts, processes, and phenomena. |
AP Biology 7.4 Population Genetics | By the end of this lesson, you'll also be able to explain
how random occurrences affect the genetic makeup of a population,
describe the role of random processes in the evolution of specific populations,
and describe the change in the genetic makeup of a population over time. |
AP Biology 7.4 Population Genetics | So now for our warm-up. |
Subsets and Splits