Most popular questions

294 Why do I only breathe out of one nostril? 2014-09-11T14:21:18.433

197 Why are so few foods blue? 2017-02-20T09:47:07.427

159 Does DNA have the equivalent of IF-statements, WHILE loops, or function calls? How about GOTO? 2015-03-04T03:10:39.550

152 How many times did terrestrial life emerge from the ocean? 2012-02-06T22:17:15.310

135 Do bacteria die of old age? 2014-09-08T08:01:51.637

121 Is there a reason why human eyesight and plants make use of the same wavelength of light? 2012-01-05T20:18:06.467

114 Why is thymine rather than uracil used in DNA? 2011-12-16T20:57:09.470

108 Are male and female brains physically different from birth? 2017-11-27T11:50:41.620

107 Why do plants have green leaves and not red? 2012-01-03T19:11:43.617

107 What is the effect of non-vaccinated people on vaccinated people? 2018-07-18T12:59:08.057

101 Can HIV be transmitted via mosquitos? 2016-04-04T12:58:33.557

97 Do beneficial viruses exist? If so, what examples are there? 2018-07-11T16:58:04.473

97 What's the evidence against SARS-CoV-2 being engineered by humans? 2020-03-14T16:22:24.860

92 Does the string "...CATCAT..." appear in the DNA of Felis catus? 2016-10-09T13:07:03.403

91 Why did the process of sleep evolve in many animals? What is its evolutionary advantage? 2011-12-24T15:10:50.830

89 Are humans the only species who drink milk as adults? 2017-08-14T04:43:36.037

85 How could humans have interbred with Neanderthals if we're a different species? 2015-10-16T18:44:23.627

83 Death because of distilled water consumption 2012-05-13T14:10:59.407

81 Why 20 amino acids instead of 64? 2012-01-14T20:40:33.610

81 Why do some bad traits evolve, and good ones don't? 2015-06-26T11:53:22.683

81 Is there an RGB equivalent for smells? 2017-01-16T13:41:23.917

81 Why is the heart not in the middle of the body? 2017-06-14T03:19:24.810

81 What's up with this leaf? 2019-06-02T19:11:05.200

75 How does the brain's energy consumption depend on mental activity? 2012-01-28T13:23:11.130

74 Why do Humans not produce Vitamin C like other mammals? 2011-12-31T16:21:58.943

74 Do animals exhibit handedness (paw-ness?) preference? 2017-03-16T10:56:18.803

74 Why shouldn't dogs eat chocolate? 2017-06-12T11:46:05.247

71 Why are there no wheeled animals? 2013-04-16T15:05:08.750

65 Do ants or other insects sleep, and if so why? 2014-09-09T12:06:11.470

65 What is the evolutionary advantage of red-green color blindness? 2016-03-10T10:05:56.590

64 Is there any evidence that sexual selection may lead to extinction of species? 2011-12-19T19:46:37.027

64 Why does evolution not make our life longer? 2014-05-02T05:33:54.220

64 What could cause a forest of bent trees? 2015-06-29T04:27:16.570

64 Why does it hurt the next day after doing significant exercise? 2017-06-22T08:56:31.680

63 Can a woman give birth to twins with different fathers? 2014-11-05T06:10:29.370

63 Are there organisms with fewer than 1000 neurons? 2017-03-24T07:03:12.553

61 How come large herbivores have such thin legs? 2017-10-10T03:52:33.000

60 Why don't mammals have more than 4 limbs? 2014-09-30T23:32:58.287

60 Why do smaller mammals move intermittently? 2015-05-29T08:12:44.547

60 A new species of small bird? 2016-08-04T19:08:21.227

59 Are the social-distancing measures implemented against SARS-CoV-2 also suppressing the spread of other viruses? 2020-06-08T12:59:35.617

58 Why do the fastest runners tend to be black? 2016-09-02T13:02:00.300

56 Life without DNA? 2011-12-15T14:20:56.700

56 What is the benefit of fever during infections? 2017-04-03T08:46:36.837

54 Human perception of time depending on age 2012-01-12T14:15:14.970

54 Why do men have nipples? 2012-05-03T05:43:42.327

54 Why isn't a virus "alive"? 2013-07-26T03:43:00.910

53 Why are there no organisms with metal body parts, like weapons, bones, and armour? (Or are there?) 2013-07-25T02:44:03.033

52 Why does cracking a joint make noise? 2014-07-22T08:02:15.937

52 Do large animals experience a meaningful delay when moving their most distant appendages? 2019-02-07T05:15:51.683