Bluebanded goby fish, about 2 to 2.5 inches long, are able to change their sex when it suits their position in social hierarchies.
Although natural sex change is exceedingly rare across the animal kingdom, bluebanded gobies are not the only creatures capable of it. Other examples include the clown fish and the limpet snail.
Groups of these fish have a skewed sex ratio in their natural environment. In other words, goby groups are not 50% male and 50% female, as one might expect. Instead, as Grober explained, “Gobies most often live in groups called harems that usually consist of one male and four to five females.”
In a natural setting, if the leading male dies, the most dominant female remaining in the group will take leadership of the harem and then physically change into a male.
Why would the female change her sex? The answer lies in evolutionary biology.
An organism’s evolutionary success depends on the number of genetic copies of itself it leaves behind in the population. So, a male fish, which mates with all of its harem’s females, has much more success in spreading genes than any given female.
For example, a male in a harem of four females has four times more reproductive success than any of his females because each individual female has only the harem’s one male partner with whom to mate.
Just as in humans, in many sex-changing fishes, social context often determines an individual’s behavior.
Hormones also play a role in the sex changes of these fish.
In one experiment, Grober and colleagues set up pairs of female bluebanded gobies, so that one fish was clearly subordinate. When they loaded up the subordinate with a potent male hormone, 11-ketotestosterone, it was able to make her look like a male, but her female-typical social behavior didn’t shift in a male direction. She continued to behave as a female.
“My team successfully demonstrated that while hormones do have a direct effect on the fish’s physical structure (like gonads, genitalia and fins), the fish's behavior answers more to its position in the social hierarchy,” he said.
What is a marriage license supposed to protect us from?
A gun license is supposed to protect us from crazy people.
A car license is supposed to protect us from bad drivers.
What is a marriage license supposed to protect us from?
Please provide your perspective below.
1. Every homeless person I have seen is either a single mom or a vet. Their cardboard sign says so.
2. Every homeless person is very religious. Their cardboard signs say, "God Bless You!"
3. Homeless people don't shave.
4. Homeless people wear dingy clothes.
5. Homeless people are thin.
6. Homeless people are always looking for work. Their cardboard sign says so. They just don't use the classifieds to look for work. They expect you to do that for them and tell them about any job openings.
7. Homeless people have backpacks to carry their worldly belongings.
how many of you fuckheads approve of the way "they" got rid of the evidence (lack of) and cost tax payers 50 million in order to rebuild a new school?
ask yourself...why didnt they tear down columbine and rebuild it?
i guess washing the blood away patching up the bullet holes was out of the question when it comes to this comunity...
how about leaving the building there and turning it into a homeless shelter, and build a new school elsewhere?
then again there probably arent very many homeless/poor people in that area.
if you cant see sandy hook was a fucking scam...you desereve to get killed by a drunk driver this weekend.
I see a lot of people yelling for peace but I have not heard of one plan for peace. " Books, not Bombs" won't work. The head mullahs won't let anyone read them. If they do, they poke their eyes out.Here's the plan:1) The US will apologize to the world for our "interference" in their affairs, past & present. You know, Hitler, Mussolini and the rest of them 'good old boys'. We will never "interfere" again.2) We will withdraw our troops from all over the world, starting with Germany, South Korea and the Philippines. They don't want us there. We would station troops at our borders. No more sneaking through holes in the fence.3) All illegal aliens have 90 days to get their affairs together and leave. We'll give them a free trip home. After 90 days the remainder will be gathered up and deported immediately, regardless of who or where they are. France would welcome them.4) All future visitors will be thoroughly checked and limited to 90 days unless given a special permit. No one from a terrorist nation would be allowed in. If you don't like it there, change it yourself, don't hide here. Asylum would not ever be available to anyone. We don't need any more cab drivers.5) No "students" over age 21. The older ones are the bombers. If they don't attend classes, they get a "D" and it's back home baby.6) The US will make a strong effort to become self sufficient energy wise. This will include developing non polluting sources of energy but will require a temporary drilling of oil in the Alaskan wilderness. The caribou will have to cope for a while.7) Offer Saudi Arabia and other oil producing countries $10 a barrel for their oil. If they don't like it, we go someplace else.8) If there is a famine or other natural catastrophe in the world, we will not "interfere". They can pray to Allah or whomever, for seeds, rain, cement or whatever they need. Besides' most of what we give them is stolen or given to the army. The people who need it most get very little, if any anyway.9) Ship the UN Headquarters to an island some place. We don't need the spies and fair weather friends here. Besides, it would make a good homeless shelter or lockup for illegal aliens.9b) Use the buildings as replacement for the twin towers.10) All Americans must go to charm and beauty school. That way, no one can call us "Ugly Americans" any longer.
That 10 step plan is better than: