ÁøÈ(Evolution) :
½Ã°£¿¡
µû¶ó »ý¹° Áý´Ü ³»¿¡ ÀϾ´Â ´ë¸³À¯ÀüÀÚ ºóµµÀÇ º¯È
I. À§ÀÇ Á¤ÀÇ´Â ÇöÀç·Î¼´Â ¾î¶² °æ¿ì¿¡µµ
¸Â´Â °ÍÀÌ´Ù. Áøȸ¦ ÀÌÇØ(?)Çϱâ À§ÇØ ¸ÕÀú °ü·ÃµÇ´Â »ý¹°ÇÐ
ºÐ¾ß¸¦ °£´ÜÈ÷ »ý°¢ÇØ º¸ÀÚ.
ÁøÈ»ý¹°ÇÐ(Evolutionary
Biology) : Áøȸ¦ ¿¬±¸ÇÏ´Â
»ý¹°ÇÐ ºÐ¾ß
ÁøÈ»ýÅÂÇÐ(Evolutionary
Ecology) : »ýÅÂÇаú ÁøÈ»ý¹°ÇÐÀÇ
Á¢¸ñ ºÐ¾ß, ȯ°æ(»ý¹°È¯°æ Æ÷ÇÔ)¿¡ µû¸¥ ÀÚ¿¬¼±Åÿ¡ µû¶ó ÀûÀÀµÈ ÇöÀç (»ýÅÂ¿Í ÇൿÀ» °¡Áø) »ý¹°·Î ÁøÈÇÑ °ÍÀ¸·Î º¸°í ÀÌ¿¡ ´ëÇÑ ½ÇÁõ ÀÚ·á ¼öÁý, ºÐ¼® ¹×
ÀÌ·Ð ¿¬±¸.
»ýÅÂÇÐ(Ecology) : »ý¹° ±º°ú
ȯ°æ(»ý¹°È¯°æ Æ÷ÇÔ)°úÀÇ °ü°è, »óÈ£¿µÇâÀ» ¿¬±¸ÇÏ´Â »ý¹°ÇÐÀÌ´Ù. °³Ã¼³ª °³Ã¼ ±¸¼ººÎºÐ(¼¼Æ÷, Á¶Á÷, ±â°ü µî)ÀÌ ¾Æ´Ï¶ó »ý¹° Áý´Ü ÀÌ»óÀ» ¿¬±¸ ´ë»óÀ¸·Î ÇÑ´Ù.
Áý´Ü À¯ÀüÇÐ(Population
Genetics) : ½Ã°£¿¡ µû¶ó
Áý´Ü ³»¿¡ ÀϾ´Â ´ë¸³À¯ÀüÀÚ ºóµµÀÇ º¯È¿Í Áý´ÜÀÇ À¯ÀüÀû ±¸¼ºÀ» ¼ö½ÄÀ¸·Î Ç¥Çö
¾çÀû À¯ÀüÇÐ(Quantitative
Genetics) : ¿¬¼Ó º¯À̸¦
³ªÅ¸³»´Â À¯ÀüÇÐ ¿¬±¸
II. ÁøÈ¿Í ÀÌ¿¡ °ü·ÃµÈ ¿ë¾î¸¦ ¸î °³ »ìÆ캸¸é¼ Áøȸ¦ °Çµå·Á º¸ÀÚ.
ÁøÈ´Â 1) »ý¹°
Áý´Ü ³»¿¡¼ °³Ã¼ °£ÀÇ °ÑÀ¸·Î µå·¯³ ¾î¶² Ư¼º(¿©±â¼± ¡®ÇüÁú, trait¡¯·Î ¸»ÇÑ´Ù)ÀÇ
Â÷ÀÌ(¿©±â¼± ¡®º¯ÀÌ¡¯·Î ¸»ÇÔ)°¡ ÀÖ¾î¾ß ÇÑ´Ù. ´ÙÀ½¿£
ÀÌ·¯ÇÑ ÇüÁú º¯ÀÌ¿¡ µû¸¥ ¡®ÀÚ¿¬¼±Åá¯ÀÌ ÀÖ¾î¾ß
Çϸç 3) ¡®ÀÚ¿¬¼±Å᯵Ǵ ÇüÁú º¯ÀÌ´Â ¡®À¯Àü¡¯µÇ¾î¾ß ÇÑ´Ù.
º¯ÀÌ(Variation) :
»ý¹°
Áý´Ü ³»ÀÇ ÇüÁúÀÇ Â÷ÀÌ. ºÒ¿¬¼Ó º¯ÀÌ¿Í ¿¬¼Ó º¯ÀÌ·Î ³ª´ ¼ö ÀÖÀ¸¸ç ¿¬¼Ó º¯ÀÌ´Â Å°, ¸ö ¹«°Ô µîÀ¸·Î Åë°èó¸® °¡´ÉÇÑ º¯·®ÀÌ¸ç ¼ö½ÄÈ °¡´ÉÇÏ¸ç ´ëºÎºÐÀÇ °æ¿ì À̸¦ ÀÌ¿ëÇÑ´Ù.
VP = VG + VE
+ (VGE)
Ç¥ÇöÇü º¯ÀÌ °ªÀº À¯ÀüÀÚÇü¿¡ ÀÇÇÑ º¯ÀÌ + ȯ°æ¿¡
ÀÇÇÑ º¯ÀÌ + (À¯ÀüÀÚÇü°ú ȯ°æÀÇ »óÈ£ÀÛ¿ë¿¡ ÀÇÇØ »ó½ÂÈ¿°ú¸¦ º¸ÀÌ´Â º¯ÀÌ)
ÀÚ¿¬¼±ÅÃ(Natural selection)
: Ç¥ÇöÇü
Â÷ÀÌ¿¡ µû¶ó ÀûÀÀµµ(Fitness) Â÷ÀÌ°¡ ³ªÅ¸³ª¸é
ÀÚ¿¬¼±ÅÃÀÌ µÈ °ÍÀÌ´Ù.
Á¤È®ÇÑ ÁøÈ»ýÅÂÇÐÀû °³³äÀ¸·Î´Â ÇÑ ¼¼´ë ³»¿¡¼ÀÇ ¡®Ç¥ÇöÇü Â÷ÀÌ¿¡ µû¸¥ ÀûÀÀµµ Â÷ÀÌ¡¯°¡ ¡®ÀÚ¿¬¼±Åá¯ÀÌ´Ù. ¼¼´ë¸¦
³Ñ¾î¼´Â ÀÚ¿¬¼±ÅÃÀº ÁøÈ·Î º»´Ù. µû¶ó¼ ÁøÈ¿¡´Â ¼¼´ë °£ÀÇ À¯ÀüÀÌ ÇʼöÀûÀÌ´Ù. ÀÚ¿¬¼±Åÿ¡´Â À¯ÀüÀÌ ÇʼöÀûÀÌÁö ¾Ê´Ù. ȯ°æ¿¡ ÀÇÇÑ Ç¥ÇöÇü Â÷ÀÌ·Î
ÀÚ¿¬¼±Åà µÇ¾îÁö³ª ±×·¯ÇÑ Ç¥ÇöÇüÀÌ À¯ÀüµÇÁö ¾ÊÀ¸¹Ç·Î ÁøÈ·Î À̾îÁöÁö ¾Ê´Â´Ù.
ÀûÀÀ(Adaptation) :
ÇöÀçÀÇ
Á¤´äÀº ¿øÀÎ-°ú-°á°ú °ü°è(Cause-and-effect
relationship)·Î º¸¸ç ÀÚ¿¬¼±Åà °á°ú°¡ ÀûÀÀÀ¸·Î ¸»ÇÑ´Ù.
µû¶ó¼ ÇöÀçÀÇ ÁøÈ·ÐÀº ¡®ÀûÀÀ(ÁøÈ)ÀÌ·Ð, Adaptative
(Evolution) Theory¡¯À» Á¤´äÀ¸·Î º¸°í ÀÌ¿¡ ´ëÇÑ ¸ðµç ¿¬±¸(½ÇÇè, ÀÚ·á ºÐ¼®, ÀÌ·ÐÈ ¼ö½ÄÈ µî)·Î
À̸¦ ½ÇÁõÇÏ·Á ÇÔ, Àü¿¡ ÇØ¿Ô´ø (ȼ®À» ¾Õ¼¼¿î) Ãß»óÀûÀÌ°í ¾ð¾îÀûÀÎ ¼³¸íÀÌ ¾Æ´Ï¶ó¡¦
µ¹¿¬º¯ÀÌ ¿Ü¿¡ ´Ù¸¥ ¿äÀÎ(À¯ÀüÀÚ ºÎµ¿, À¯ÀüÀÚ À̵¿, Áý´Ü ÀÌÁÖ, ÀÚ¿¬¼±ÅÃ
µî)µµ ÁøÈ¿¡ Áß¿äÇÑ ¿äÀÎÀÌÁö¸¸ Áö±¸ »ý¸íü ¿ª»ç¸¦ µ¹ÀÌÄÑ º»´Ù¸é µ¹¿¬º¯ÀÌÀÇ Á߿伺À» ÀǽÉÇÒ ¼ö´Â ¾ø´Ù. ¹æÇ⼺ ¼±ÅÃ(Directional selection)¿¡¼ Áö¼ÓÀûÀÎ
µ¹¿¬º¯ÀÌ°¡ ¾ø´Ù¸é ¼ö½Ê ¼¼´ë¿¡ À̸£¸é ±× ¹æÇ⼺ ¼±Åà ÈûÀÌ ¼ÒÁøµÇ¾î ´õ ÀÌ»ó ÁøÈ´Â ÀϾÁö ¾ÊÀ» °ÍÀÌ´Ù.
±ä ½Ã°£¿¡ °ÉÄ£ ÁøÈ¿¡´Â µ¹¿¬º¯ÀÌ°¡ ÇÊ¿¬ÀûÀÏ °ÍÀÌ´Ù(µ¹¿¬º¯ÀÌ ¹ß»ý°ú ±× È¿°ú°¡ ³ªÅ¸³¯ È®·ü ÀÌÇØ, ¿¬±¸, Çؼ®ÀÌ ¾î·Æ°í ÀÌ¿¡ ´ëÇÑ ÀϹÝÀÇ »ý°¢°ú Àü¹® ¿¬±¸ÀÚÀÇ »ý°¢ÀÌ ÀüÇô ´Ù¸£°í µîÀÇ ÇØ°áµÇÁö ¸øÇÑ ¼ö ¸¹Àº ¹®Á¦¿¡µµ
ºÒ±¸ÇÏ°í¡¦)
III. ´Ù½Ã ¿ø·¡ ¸ÕÀú ½è´ø À̾߱⸦ º¸¸ç Áøȸ¦ ´Ù½Ã º¸±â·Î ÇÑ´Ù.
1.
´ÙÀ©ÀÇ ÁøÈ·Ð
3 key words : Evolution, Speciation
by Natural Selection
ÀÚ¿¬¼±ÅÃÀÇ Á߿伺
(1) º¯ÀÌ´Â ¸ðµç »ý¹°ÀÇ ±âº»Àû Ư¼ºÀÌ´Ù.
(2) ¸ðµç »ý¹°Àº ÈļÕÀ» °úÀ×»ý»êÇϹǷΠ´ëºÎºÐÀÇ ÈļյéÀº ¹ø½Ä½Ã±â
ÀÌÀü¿¡ Á״´Ù.
(3) ¸ÔÀÌ, °ø°£, ¹è¿ìÀÚ µîÀÇ ÀÚ¿ø¿¡ ´ëÇÑ °æÀïÀÌ ¹ß»ýÇÑ´Ù.
(4) °æÀïÇÏ´Â ÀÚ¿øÀ» °¡Àå Àß È¹µæÇÏ°í ÀÌ¿ëÇÏ´Â °³Ã¼µéÀÌ »ýÁ¸ÇÑ´Ù.
(5) ¼±ÅÃµÈ ÇüÁúÀº ´ÙÀ½ ¼¼´ë·Î Àü´ÞµÈ´Ù.
2. Çϵð-¿ÍÀιö±×
ÆòÇü
(1) ´ë¸³À¯ÀüÀÚ ºóµµ ÆòÇü
: p + q = 1
(2) À¯ÀüÀÚÇü ºóµµ ÆòÇü :
p2 + 2pq + q2 = 1
(3) ÆòÇüÀº Á߸³ (ÆòÇüÀÌ
±³¶õµÇ¸é »õ·Î¿î ´ë¸³ À¯ÀüÀÚ ºóµµ¿¡¼ ÆòÇüÀÌ ÀÌ·ç¾îÁø´Ù)
3. H-W ÆòÇü °¡Á¤Àº
´ÙÀ½ÀÇ 4 °¡Áö°¡ ¾ø´Â
°æ¿ìÀÌ´Ù.
1) µ¹¿¬º¯ÀÌ, 2) ÀÚ¿¬
¼±Åà 3) ¼º ¼±Åà Æ÷ÇÔ, 4) ÀÌÁÖ(Áï À̵¿)
¶ÇÇÑ Áý´Ü Å©±â°¡ ¸Å¿ì Ä¿¾ß ÇÑ´Ù. °°Àº
¡®¹ø½Ä·Â¡¯µµ À̾߱⠵dzª »ç½Ç»ó ÀÌ´Â ¡®¼º ¼±Åᯰú ´õºÒ¾î ¡®ÀÚ¿¬¼±Å᯿¡ Æ÷Ç﵃ ¼ö ÀÖ´Ù.
Çϵð-¿ÍÀιö±× ÆòÇüÀº ¸¹Àº »ç¿ë °¡Ä¡°¡
Àִµ¥
(1) Áý´Ü ³» ƯÁ¤ ´ë¸³ À¯ÀüÀÚ ºóµµ¿Í À¯ÀüÀÚÇü ºóµµ¸¦ ¿¹Ãø, ¿¬±¸Çϴµ¥ »ç¿ëµÈ´Ù.
¿¹) ¹Ì±¹ ³» ¾Ëºñ³ë
ȯÀÚ ºñÀ²ÀÌ 1/20000 (20000 ¸í ´ç 1 ¸í ²ÃÀÌ´Ù.)
±×·³ q2 = 1/20000 = 0.00005 (0.005 %)
q = 0.00707
p = 1 – q = 0.99293
(p + q) 2 = p2
+ 2pq + q2 = 1
p2 = 0.9859 , 2pq = 0.01404,
q2 = 0.00005
Áï, À¯ÀüÀÚ Ç®¿¡¼
¿¼º ´ë¸³À¯ÀüÀÚ q ´Â 0.7 %, ¿ì¼º ´ë¸³À¯ÀüÀÚ p ´Â 99.3 % Á¸ÀçÇÑ´Ù. ¾Ëºñ³ë
ȯÀÚ´Â ¿¼ºÀ¯ÀüÀÚ ½ÖÀÌ Á¸ÀçÇØ¾ß ¹ß»ýµÇ¹Ç·Î 0.005% Á¤µµ·Î Àû°Ô ³ªÅ¸³´Ù. ±×·¯³ª ¿¼ºÀ¯ÀüÀÚ¸¦ Áö³æÀ¸³ª Ç¥ÇöµÇÁö ¾Ê°í ´ÙÀ½ ¼¼´ë¿¡ ÀÌ À¯ÀüÀÚ¸¦ Àü´ÞÇÏ´Â ÀÌÇü ´ë¸³À¯ÀüÀÚ Á¶ÇÕ(pq)´Â 1.4 %·Î ¸Å¿ì ³ô´Ù. ¿¼ºÀ¯ÀüÀÚ¸¦
Áö´ÏÁö ¾ÊÀº ¼ø¼öÇÑ À¯¼ºÀ¯ÀüÀÚ Á¶ÇÕÀº 98.6 % ÀÌ´Ù.
(2) Çϵð-¿ÍÀιö±× °¡Á¤¿¡ ¹þ¾î³ª¸é Áøȸ¦ ÇÑ´Ù.
ÀÌ°ÍÀÌ ÁøÈ¿¡ ´ëÇÑ Áß¿äÇÑ ÀÌÇØÀÌ´Ù.
4. µû¶ó¼
1) ÁøÈ´Â °³Ã¼ ¹®Á¦°¡ ¾Æ´Ï¶ó Áý´ÜÀÇ ¹®Á¦ÀÌ´Ù.
2) ÁøÈ´Â Áý´ÜÀÇ À¯ÀüÀÚ Ç®(¡®À¯ÀüÀÚ ±Þ¿ø¡¯À¸·Î ¹ø¿ªÇϱ⵵)¿¡¼
´ë¸³À¯ÀüÀÚ ºóµµ°¡ º¯ÈµÇ´Â °ÍÀÌ´Ù.
3) ÁøÈ´Â µ¹¿¬º¯ÀÌ, ÀÚ¿¬¼±ÅÃ(¼º ¼±ÅÃ) µîÀ¸·Î ÀϾÙ.
5. À§ À̾߱⿡ µû¸¥ ¿ë¾î »ìÆ캸±â·Î
µ¹¿¬º¯ÀÌ(mutation) :
À¯ÀüÀÚ
Ç®¿¡ »õ·Î¿î À¯ÀüÀÚ¸¦ ´õÇÏ°Ô µÈ´Ù.
À¯ÀüÀÚ ºÎµ¿(Gene drift) : Á¤ÇØÁø
°³Ã¼ ¼ö °£ÀÇ ¹«ÀÛÀ§ÀûÀÎ À¯ÀüÀÚ ÀçÁ¶ÇÕ °á°ú·Î ƯÁ¤ ´ë¸³ À¯ÀüÀÚ ºóµµ°¡ ³·¾ÆÁö°í ¾ÆÁÖ Áý´Ü¿¡¼ ¾ø¾îÁú È®·üÀÌ Á¸ÀçÇÑ´Ù. ÀÏ´Ü À¯ÀüÀÚ Ç®¿¡¼ Á¦°ÅµÇ¸é ´Ù½Ã´Â ³ªÅ¸³ªÁö ¾Ê°Ô µÈ´Ù.
ÀÚ¿¬¼±ÅÃ(Natural selection) :
»ýÁ¸À²(¼º¼±ÅÃ, ¹ø½Ä·Â, ¹ø½ÄȽ¼ö,µî)ÀÌ Ç¥ÇöÇü º¯ÀÌ¿¡ µû¶ó ´Ù¸£°í ÀÌ·¯ÇÑ Ç¥ÇöÇü º¯ÀÌ´Â À¯ÀüÀÚÇü°ú
¿¬°üµÇ¾î ÀÖ¾î Èļտ¡ Àü´ÞµÈ´Ù¸é ÈÄ´ëÀÇ À¯ÀüÀÚ Ç®ÀÇ À¯ÀüÀÚ ºóµµ´Â ¹Ù²î°Ô µÈ´Ù. ¼±ÅÃÀÇ ´ë»óÀÌ µÇ´Â
ƯÁ¤ÇÑ Ç¥ÇöÇüÀÇ Æ¯¼ºÀ» ¡®ÇüÁú(Trait)¡¯¶ó ÇÑ´Ù.
ÀûÀÀµµ(Fitness) :
ÇÑ
À¯ÀüÀÚÇü¿¡ ÀÖ¾î ÃÑüÀûÀÎ »ýÁ¸À²(´ÙÀ½ ¼¼´ë¿¡ À¯ÀüÀÚ¸¦ Àü´ÞÇÏ´Â)¿¡
´ëÇÑ »ó´ëÀûÀÎ ±â¿©µµ·Î 1~0 »çÀÌÀÌ´Ù. °¡Àå Å« °ªÀÌ ¹°·Ð 1ÀÌ´Ù. ¹ø½Ä·ÂÀ» ³·Ãß´Â ±â¿©µµ¸¦
s, t ¶óÇϸé ÀûÀÀµµ W = 1- s ÀÌ´Ù. ¡®¿¼ºÄ¡»ç¡¯ÀÎ °æ¿ì s = 1, W = 0 ÀÌ µÈ´Ù.
ÀûÀÀµµ ±¸¼º¿ä¼Ò : »ýÁ¸´É·Â, ¼º ¼±Åà ´É·Â, »ý½Ä´É·Â(»ý»ê´É·Â) ÀÌ ¿Ü¿¡µµ ¾ö¸¶ÀÇ ÀÚ±Ãȯ°æ(Marternal Effects ·Î ÁÖ¿äÇÑ
¿ä¼Ò. ȯ°æÀû ¿µÇâÀ¸·Î º¸´Â °ßÇصµ ÀÖÀ¸³ª À¯ÀüÀû ¿µÇâÀ¸·Î º¸´Â °ÍÀÌ ´õ ÁÁÀ» µí). ´õ ³ª¾Æ°¡ ¾ÆÀ̸¦ µ¹º¸´Â ´É·Â(K Àü·«°¡¿¡¼ ¹®Á¦°¡ µÇµíÀÌ ÀÌ·±
ÇüÁúÀÌ À¯ÀüµÈ´Ù¸é °ü·Ã À¯ÀüÀÚÇüÀÇ ºóµµ´Â Áõ°¡µÉ °ÍÀÌ)
¼±Åà ȿ°ú
1)
¹æÇ⼺
¼±ÅÃ(Directional selection) – ȼ® Áõ°Å¸¦ °¡Áö°í ¸»°ú ±â¸°ÀÇ ¿¹¸¦ µç´Ù. ġŸ¿Í ÀÓÆç¶óÀÇ ÃÖ±ÙÀÇ °øÁøÈ ¿¬±¸¿¡¼µµ Àß ³ªÅ¸³´Ù. Æò±ÕÀ» ¹þ¾î³
±Ø´ÜÀûÀÎ ¹üÀ§°¡ ¼±ÅõȴÙ(¹Ù¶÷Á÷Çϰųª ¶Ç´Â ¹Ù¶÷Á÷ÇÏÁö ¾Ê°Ô).
2)
¾ÈÁ¤È
¼±ÅÃ(Stabilizing selection) – Ç¥ÇöÇüÀÇ ¾à ³¡À» Á¦°ÅÇÏ¿© µ¿ÀÏÇÑ Æò±ÕÀ» À¯ÁöÇÑ´Ù. ½Å»ý¾Æ ¹«°Ô¸¦ ¿¹·Î µç´Ù. ³Ê¹« °¡º±°Å³ª ³Ê¹« ¹«°Å¿î žƴ »ýÁ¸
°¡´É¼ºÀÌ ÀÛ¾ÆÁø´Ù.
3) ºÐ¸®Àû ¼±ÅÃ(disruptive selection) – Ç¥ÇöÇü ºÐÆ÷ÀÇ Áß¾Ó¿¡ ÀÖ´Â °³Ã¼µéÀ» ¼Ò¸ê½ÃÅ°°í ¾ç³¡¿¡ ÀÖ´Â °³Ã¼µé¿¡°Ô
À¯¸®ÇÏ°Ô ÀÛ¿ëÇÑ´Ù. ³ë¶û ÃÊÆĸ® Áý´Ü¿¡¼ ¿· °¡½¿ °¸ð ¼ö°¡ ºÐ¸® ¼±ÅõǴ ¿¹¸¦ ¼º°øÀûÀ¸·Î °üÂûµÇ¾ú´Ù.
IV. ¸¶Áö¸·À¸·Î ¾Æ·¡ Âü°í ¿µ¹®À» ÀÐ¾î º¸¸é ¹ºÁö ¸ð¸£´Â À̾߱Ⱑ Á» ´õ È®½ÇÇÏ°Ô °¨ Àâ°Ô µÉ °ÍÀÌ´Ù.
When Charles Darwin and Alfred Russell
Wallace proposed theory of evolution by natural selection, the concepts of
evolution and speciation were not new. Darwin introduced The Origin with ¡°An
Historical Sketch,¡± in which he summarized the work of 34 previous authors who
had speculated on evolution and the origin of species. What was new about
Darwin and Wallace¡¯s proposition was natural selection as the mechanism of
evolutionary change. Darwin further proposed that natural selection was a unifying
process that natural selection was a unifying process that account for
adaptation, for speciation, and hence for the diversity of life on earth.
However, despite its logical consistency,
natural selection was not accepted as a necessary or sufficient explanation for
adaptation until the ¡°evolutionary synthesis¡± of the mid-20th century, when
knowledge from population and quantitative genetics, natural history(e.g.,
biogeography, ecology, behavior), systematics, and paleontology merged to form
the unified theory of adaptive evolution known as neo-Darwinism. Since that
time, natural selection has been accepted as the universal mechanism leading to
adaptation, and the two terms have become so closely associated as to be almost
tautological.
The biological
sciences now generally define evolution
as being the sum total of the genetically inherited changes in the individuals
who are the members of a population's gene pool. It is clear that the
effects of evolution are felt by individuals, but it is the population as a
whole that actually evolves. Evolution is simply a change in frequencies
of alleles in the gene pool of a population. For instance, let us assume
that there is a trait that is determined by the inheritance of a gene with two
alleles--B and b.
If the parent generation has 92% B and 8% b and their offspring collectively have 90% B and 10% b, evolution
has occurred between the generations. The entire population's gene pool
has evolved in the direction of a higher frequency of the b allele--it was not just those individuals who
inherited the b allele who evolved.
This definition
of evolution was developed largely as a result of independent work in the early
20th century by Godfrey Hardy, an
English mathematician, and Wilhelm Weinberg,
a German physician. Through mathematical modeling based on probability,
they concluded in 1908 that gene pool frequencies are inherently stable but
that evolution should be expected in all populations virtually all of the
time. They resolved this apparent paradox by analyzing the net effects of
potential evolutionary mechanisms.
Hardy, Weinberg,
and the population geneticists who followed them came to understand that
evolution will not occur in a population if seven conditions are met:
1) mutation is
not occurring
2) natural
selection is not occurring
3) the
population is infinitely large
4) all members
of the population breed
5) all mating is
totally random
6) everyone
produces the same number of offspring
7) there is no
migration in or out of the population
2010-06-09, ´Ù½Ã ãÀ½, °û³ëÅÂ