生物学者を悩ませた「野生動物のホモセクシュアル・パラドクス」が解決か？

Gender benders in the animal kingdom

Same-sex behaviour is well-documented in more than 500 species of animals and birds. For as long as humans have lived, homosexuality
has occurred in every culture. If the point of sex is procreation, why has evolution not weeded out non-productive sex?

The Laysan albatross is the epitome of monogamy, with the pair committed to each other for the long haul. But biologists discovered
that about 60 per cent of the population in Oahu, Hawaii, is female, and during the breeding season, about 30 per cent of the pairs
are female-female.

Much to the concern of sheep farmers, about eight per cent of all rams are homosexual, refusing to mate with ewes. These ram-preferring
rams have a smaller hypothalamus, the part of the brain that controls reproductive functions, than heterosexual rams.

Although same-sex behaviour appears to be genetic in fruit flies, no gene for gayness has been found in mammals. Intriguingly, identical
human twins share the same genetic material, but they don’t always share the same sexual orientation.

In December 2012, a team led by William Rice, an evolutionary biologist at University of California, Santa Barbara, theorised that
epigenetic marks may hold the answer. Residing beside DNA, they direct how, when, and which genes switch on in response to the environment
throughout one’s life. In the womb, epi-marks protect boys from underexposure and girls from overexposure to testosterone.

続きます

ハングルでおｋ

ホモは遺伝するってのか

>>1の続き

These switches are not typically hereditary, but sometimes, they get passed on. In such cases, girls inherit the marks from their fathers
and become masculine, while boys receive from their mothers and become feminine.

Homosexuality may indirectly benefit other members of the family like increased fertility in women and appropriate hormonal controls in parents.

Other scientists wonder if homosexuality serves any purpose at all. Perhaps it rides piggyback on another beneficial adaptation that gets
selected again and again, and homosexuality gets inadvertently chosen too.

There probably is no single explanation for a behaviour found in so many different creatures. Perhaps it is a result of gender shortage for
some, male bonding, and genetic side-effect in others. Among dogs, not all same-sex mountings are sexual, but a show of dominance.

Most of our attempts to answer the paradox of homosexuality focus on the barrenness of same-sex. But many sexual acts are non-reproductive.
Since sex also gives pleasure, to that end, homosexuality is no different from heterosexuality. Perhaps that’s all there is to it.
http://www.thehindu.com/features/metroplus/society/gender-benders-in-the-animal-kingdom/article5613804.ece

参考画像
http://1.bp.blogspot.com/-GKabljPRXQE/UTW32y0ZcjI/AAAAAAAAA18/Cr2znx0rhuU/s1600/deer%2Bthreesome.jpg
http://polari.polariarts.netdna-cdn.com/wp-content/uploads/2011/11/Gay-animals.jpg
http://upload.wikimedia.org/wikipedia/commons/7/7f/Males_Anas_platyrhynchos_2_.jpg
http://dericbownds.net/uploaded_images/Bisex_peng.jpg
依頼161

If the point of sex is procreation, why has evolution not
weeded out non-productive sex?

↑

これに対する答は有るんだろうな？

うちのキンカチョウもオス二匹でカゴに入れてるけどホモ行為に耽ってるよ

なぜ神はアナルを気持ち良く創りたもうたのか

日本語でおｋ

うんこする快感なんだろ
決して神はアナルに挿入する事は想定していないだろう
だから脱肛したりと壊れる

ちなみにホモ＋ネクロフィリアを併発してる野生動物も観察されてる
http://4.bp.blogspot.com/-gEhzudeN88E/TfsaUeb7mtI/AAAAAAAAAuQ/uDEp01Cpd3c/s640/Bird%2Bmourns%2Bdeath%2Bof%2Bmate%2B003.jpg

「気持ち良ければオスでもメスでも関係無い」

何これ？

解決してねーじゃん
いい加減なスレタイつけるなよ