史前素描的愛好者們現(xiàn)在可以用更少的猜測為自己喜愛的古昆蟲填色了,。
從甲蟲到蝴蝶的現(xiàn)代昆蟲因?yàn)樗鼈兊慕饘偕{(diào)而聞名于世,。這些復(fù)雜且斑斕的色彩模式起源于沿著生物外骨骼外層的細(xì)微結(jié)構(gòu)發(fā)生的調(diào)整，例如超薄組織的交互層向不同方向發(fā)出的反射光,。
許多甲蟲化石也具有類似的色彩,，但是科學(xué)家們無法確定的是石化過程是否會改變它們的色彩。
為了解開這道關(guān)于顏色的難題,，美國耶魯大學(xué)的古生物學(xué)家Maria E. McNamara和同事在顯微鏡下對古老昆蟲——距今約1500萬年到5000萬年——的納米結(jié)構(gòu)進(jìn)行了分析,。
果然，結(jié)果顯示,，與它們的外骨骼結(jié)構(gòu)所表現(xiàn)的顏色相比,，許多甲蟲具有不同的顏色,。研究小組在本周的英國《皇家學(xué)會學(xué)報(bào)B》網(wǎng)絡(luò)版上報(bào)告了這一研究成果。
研究人員斷定,，石化過程中的分子變化很可能將甲蟲的顏色向著彩色光譜的紅色端推進(jìn),，例如，一只通常為黃色的甲蟲會變?yōu)槌壬?。（生物?Bioon.com）
doi:10.1098/rspb.2011.1677
PMC:
PMID:
The original colours of fossil beetles
McNamara, Maria E.; Briggs, Derek E. G.; Orr, Patrick J.; Noh, Heeso; Cao, Hui
Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complexnanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts,but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is alwaysreal. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimensare generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other keycuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can inferthat the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructionsof the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved coloursare offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticleduring fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to beidentified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.
