1 00:00:01,920 --> 00:00:06,600 Speaker 1: Welcome to brain Stuff, a production of iHeart Radio. Hey 2 00:00:06,600 --> 00:00:09,280 Speaker 1: brain Stuff. Lauren bog Obam here with a classic episode 3 00:00:09,280 --> 00:00:12,720 Speaker 1: from our erstwhile host, Christian Sagar. This is what I've 4 00:00:12,720 --> 00:00:14,600 Speaker 1: been thinking about because of all the time I've been 5 00:00:14,640 --> 00:00:17,599 Speaker 1: spending when I am out in public interacting with people 6 00:00:17,640 --> 00:00:19,840 Speaker 1: who are wearing a covering over the lower half of 7 00:00:19,880 --> 00:00:22,800 Speaker 1: their face. The question of the day is why do 8 00:00:22,880 --> 00:00:28,560 Speaker 1: we have eyebrows? Hey, brain stuff? It's Christian Saga, and 9 00:00:28,600 --> 00:00:32,760 Speaker 1: I'm here to tell you why human beings have eyebrows, 10 00:00:32,880 --> 00:00:35,680 Speaker 1: because look at them. Take clus look, go over to 11 00:00:35,680 --> 00:00:39,400 Speaker 1: the mirror. Look, aren't they just ridiculous? I mean, they're 12 00:00:39,440 --> 00:00:44,000 Speaker 1: also very well manicured, but they're also ridiculous. Now, scientists 13 00:00:44,040 --> 00:00:47,800 Speaker 1: aren't entirely sure why we have this hair, but they 14 00:00:47,840 --> 00:00:50,920 Speaker 1: have a pretty good guess. The arch shape of the 15 00:00:50,960 --> 00:00:55,520 Speaker 1: eyebrow diverts rain or sweat around to the sides of 16 00:00:55,560 --> 00:00:59,960 Speaker 1: our face, keeping our eyes relatively dry, and the most 17 00:01:00,240 --> 00:01:03,080 Speaker 1: obvious advantage of this is that it allows us to 18 00:01:03,120 --> 00:01:07,600 Speaker 1: see clearly even when we're sweating a lot. Diverting the 19 00:01:07,680 --> 00:01:11,200 Speaker 1: sweat away is also good because the salt in sweat 20 00:01:11,480 --> 00:01:15,480 Speaker 1: irritates our eyes. But just to test things. I shook 21 00:01:15,560 --> 00:01:18,640 Speaker 1: a salt shaker into my eye and take it from me. 22 00:01:18,880 --> 00:01:23,560 Speaker 1: It burns like hell fire. Eyebrows are a very significant 23 00:01:23,600 --> 00:01:26,720 Speaker 1: aspect of our appearance. They are one of the most 24 00:01:26,760 --> 00:01:30,120 Speaker 1: distinctive features that make up our faces, and we pay 25 00:01:30,160 --> 00:01:33,800 Speaker 1: a lot of attention to them and look. Eyebrows are 26 00:01:33,880 --> 00:01:37,600 Speaker 1: also one of the most expressive facial features. One of 27 00:01:37,640 --> 00:01:40,959 Speaker 1: the clearest ways we're telling somebody what we're thinking is 28 00:01:41,000 --> 00:01:44,840 Speaker 1: to simply move our eyebrows up and down. But what 29 00:01:44,959 --> 00:01:49,240 Speaker 1: if we didn't have eyebrows. Scientists have thought about this 30 00:01:49,280 --> 00:01:52,240 Speaker 1: as well, and they think that if we didn't have eyebrows, 31 00:01:52,560 --> 00:01:57,040 Speaker 1: we would have gotten instead these long snuffle luck bagus 32 00:01:57,080 --> 00:02:02,600 Speaker 1: style eyelashes, as well as far protruding foreheads, which could 33 00:02:02,640 --> 00:02:05,320 Speaker 1: have been kind of useful because we could put things 34 00:02:05,440 --> 00:02:08,160 Speaker 1: up there I don't know, like like our keys, but 35 00:02:08,480 --> 00:02:12,200 Speaker 1: rain or sweat would then drop from that ledge on 36 00:02:12,240 --> 00:02:15,240 Speaker 1: our face straight away down onto the rest of our 37 00:02:15,280 --> 00:02:19,120 Speaker 1: face without getting into our eyes. So all right, way 38 00:02:19,160 --> 00:02:22,040 Speaker 1: to go, evolution for not making us look like that. 39 00:02:26,680 --> 00:02:29,560 Speaker 1: Today's episode was written by someone I could not figure 40 00:02:29,560 --> 00:02:32,320 Speaker 1: out who, but it was produced by Tyler Clang. For 41 00:02:32,440 --> 00:02:33,959 Speaker 1: more on this and lots of other topics. Is it 42 00:02:34,040 --> 00:02:36,560 Speaker 1: how stuff works dot com brain Stuff is production of 43 00:02:36,600 --> 00:02:38,919 Speaker 1: I heart Radio for more podcasts to my heart Radio. 44 00:02:39,160 --> 00:02:41,760 Speaker 1: Is it the heart radio app, Apple Podcasts, or wherever 45 00:02:41,800 --> 00:02:43,080 Speaker 1: you listen to your favorite shows,