Editors' Choice

Science  04 Jan 2019:
Vol. 363, Issue 6422, pp. 40
  1. Evolution

    Sing on high, dance on the floor

    1. Caroline Ash

    A Raggiana bird-of-paradise from the Southern Highlands, Papua New Guinea


    The frugivorous, polygamous, and wildly glamorous birds of paradise are a puzzle to evolutionary biologists. What is sexual selection acting on to result in such extremely visual, behavioral, and aural diversity among these related species? Ligon et al. analyzed 961 video clips, 176 audio clips, and 393 museum specimens. They concluded that females are selecting on the combined sensory assault from song, display, and plumage color, resulting in a “courtship phenotype.” Although all elements are required for successful courtship, there is room for variation depending on environmental constraints. Song predominates in the canopy, where it is unimpeded by twigs and branches, whereas flashy behavioral display is most effective on the gloomy forest floor.

    PLOS Biol. 16, e2006962 (2018).

  2. Human Genetics

    Alzheimer's disease in admixed people

    1. Laura M. Zahn

    Several genes have been identified that increase the risk of late-onset genetic disorders, such as Alzheimer's disease (AD). Specifically, the ApoE ε4 allele is associated with a higher risk of developing AD. However, individuals of African ancestry that carry this variant appear to be less prone to developing AD. Rajabli et al. examined AD cases and controls in admixed individuals of Puerto Rican and African-American descent and found that individuals who carried an African ApoE ε4 background had less risk of developing the disease. It seems the African variant of ApoE ε4 contains protective genetic variants.

    PLOS Genet. 14, e1007791 (2018).

  3. Plant Science

    Essential metal for plants

    1. Pamela J. Hines

    Although zinc (Zn) is an essential micronutrient for plants and humans, much of the world's agricultural land is deficient in Zn. Sinclair et al. studied plants that are unable to deliver Zn into their own xylem. The plant shoots were thus internally starved regardless of whether Zn was available from the root. The Zn-starved shoots signaled to roots to increase Zn supplies. In response, the roots up-regulated expression of the genes encoding metal transport/tolerance protein 2 (MTP2) and heavy metal ATPase 2 (HMA2). Local Zn deficiency in roots left these same genes unaffected. It seems that Zn taken up in lateral roots is transported into the endoplasmic reticulum by MTP2, thus gaining access to the intercellular symplastic network. The Zn then progresses from outer epidermal cells toward the core of the root, where it is exported by HMA2 into the xylem for transport to the shoot. The shoot asks for what it needs, and the root delivers.

    Plant Cell 30, 2463 (2018).

  4. Skin

    Roots of acne

    1. Priscilla N. Kelly

    Most people experience a bout of acne at some stage in their life. For an unlucky few, the skin condition feels relentless and can evade treatment. Petridis et al. performed a DNA study of individuals with acne vulgaris and found that those affected share similar, but surprising, genetic mutations. Homing in on 15 regions of the genome, they identified a series of culprit genes that controlled hair growth and follicle formation. This discovery lends weight to the idea that hair follicle shape creates a milieu susceptible to bacterial colonization and inflammation.

    Nat. Commun. 9, 5075 (2018).

  5. Plastic Pollution

    Scallops seasoned with nanoplastics

    1. Julia Fahrenkamp-Uppenbrink

    The great scallop (Pecten maximus) reveals details about the uptake of nanoplastics by marine organisms.


    Microplastics are present in marine environments worldwide. As these particles break down further, they form nanoplastics, which are harder to detect. Nanoplastics also can enter the environment directly from commercial products such as paints and cosmetics. Al-Sid-Cheikh et al. investigate the uptake of such nanoplastics by scallops at predicted environmental concentrations. The authors use radiocarbon labeling to track the nanoplastics within the scallop tissues. Uptake differs depending on particle size: Larger nanoparticles accumulate in the intestine, whereas smaller nanoparticles are dispersed through the entire scallop body. After exposure to nanoplastics ceased, smaller nanoparticles were no longer detected after 14 days, but some larger nanoparticles persisted for more than 48 days. The presence of the smaller nanoparticles in muscle tissue suggests that the particles can cross epithelial membranes.

    Environ. Sci. Technol. 52, 14480 (2018).

  6. Relationship Science

    Ending a relationship

    1. Tage S. Rai

    When deciding to end a relationship, people may consider the feelings of their partners as well as their own. Joel et al. investigated whether decisions to break up are driven in part by perceptions of a partner's dependence on the relationship. They found that participants were less likely to initiate a breakup with their partners when they felt that their partners were more dependent on the relationship for psychological well-being, even when participants were unsatisfied in the relationship. Even participants who were actively considering breaking up with their partners were less likely to do so if they felt their partners depended on the relationship. These results suggest that people exhibit costly, prosocial preferences in relationships even when they may wish to leave them.

    J. Pers. Soc. Psychol. 115, 805 (2018).

  7. Opportunity Denied

    The inequality of innovation

    1. Brad Wible

    A lack of social capital can undermine a child's likelihood of becoming an inventor, regardless of her inventive ability. Using U.S. patent records for 1.2 million inventors, combined with tax records and other data, Bell et al. show how children from high-income families are several times more likely to become inventors than those from lower-income families, even when they have comparable math abilities. Children who grow up in areas where innovation and patenting are more common are more likely to patent as well, and particularly in the same class of technologies that had a high innovation rate in their childhood communities.

    Quart. J. Econ. 10.1093/qje/qjy028 (2018).