(dissenting, with whom O’Connor, J., joins). At the outset I wish to make clear that my views are not moti-voted by any disapproval of the two petitioners here or their life-style. The judge has found that the petitioners have provided the child with a healthy, happy, stable family unit. The evidence supports the judge’s findings. Nor is my disagreement with the court related to the sexual orientation of the petitioners. I am firmly of the view that a litigant’s expression of human sexuality ought not determine the outcome of litigation as long as it involves consenting adults and is not harmful to others. However, the court’s decision, which is inconsistent with the statutory language, cannot be justified by a desire to achieve what is in the child’s best interests. Indeed, those interests can be accommodated without doing violence to the statute by accepting the alternative to joint adoption suggested by the Probate Court judge (ante at 206 n.l); that is, permitting Helen to adopt Tammy while al*218lowing Susan to retain all her parental rights and obligations. This is essentially what the court accomplishes in part 2 {ante at 216) of its opinion. By this simple expedient, all of the court’s concerns about protecting filial ties and avoiding legal limits are put to rest without invading the prerogatives of the Legislature and giving legal status to a relationship by judicial fiat that our elected representatives and the general public have, as yet, failed to endorse.
The court concludes that the Probate and Family Court has jurisdiction to grant a joint petition for adoption by two unmarried cohabitants because they meet the statutory requirements of G. L. c. 210, § 1, and it is in the child’s best interests to be adopted by both. General Laws c. 210, § 1, enumerates who may petition for adoption.1 In accordance with the statute, a petitioner of full age may petition to adopt. If a person is married and has a competent spouse, the spouse is required to join in the petition to adopt. See Mitchell v. Mitchell, 312 Mass. 154, 163 (1942); Davis v. McGraw, 206 Mass. 294, 298 (1910). If a husband and wife fail jointly to petition for adoption, a decree or judgment granting the adoption is void. Lee v. Wood, 279 Mass. 293, 295-296 (1932). A minor may petition for adoption of his or her natural child or may join in the petition of his or her spouse when the child is the natural child of one of the parties. G. L. c. 210, § 1. The court has also interpreted the statute as permitting a biological parent of full age to petition for the adoption of his or her own child. Curran, petitioner, 314 Mass. 91, 95 (1943). There is, however, nothing in the stat*219ute indicating a legislative intent to allow two or more unmarried persons jointly to petition for adoption.2 Massachusetts became the first common law jurisdiction to authorize judicially approved adoption with parental consent by statute. St. 1851, c. 324. Presser, The Historical Background of the American Law of Adoption, 11 J. Fam. L. 443 (1972). General jurisdiction over adoptions is granted to the Probate and Family Court, G. L. c. 215, § 3, and can be exercised only as provided by the Legislature with the paramount concern, purpose, and focus of adoption proceedings being the welfare of the child. Adoption of a Minor, 386 Mass. 741, 743 (1982). See C.P. Kindregan & M.L. Inker, Family Law and Practice § 1851 (1990 & Supp. 1993). Since adoption is a creature of the Legislature, Davis v. McGraw, supra at 297, and in derogation of the common law, the statute must be strictly construed. See Mitchell v. Mitchell, 312 Mass. 154, 161 (1942); Beloin v. Bullett, 310 Mass. 206, 210 (1941); Purinton v. Jamrock, 195 Mass. 187, 197 (1907). The plain meaning of a statute cannot be expanded or altered where the Legislature establishes specific criteria or classifications to be satisfied. See Holahan v. Medford, 394 Mass. 186, 189 (1985); Martinelli v. Burke, 298 Mass. 390, 392 (1937). Unless one of the enumerated potential petitioners brings an adoption petition, the court lacks the jurisdiction to entertain the petition. Mitchell v. Mitchell, supra at 160-161. In the present case, the petitioners are two unmarried persons seeking to adopt a child. The statute only permits joint petitions • for adoption by married persons. See Adoption of Meaux, 417 So. 2d 522, 523 (La. Ct. App. 1982) (unmarried natural parents may not jointly adopt own illegitimate child); Matter of Adams, 189 Mich. App. 540, 544 (1991) (inconsistent with purpose and scope of adoption *220statute to allow joint adoption of two unmarried petitioners); In re Jason C., 129 N.H. 762, 765 (1987) (two unmarried persons may not jointly adopt child). Contra Adoption of B.L.V.B., 160 Vt. 368 (1993) (permitting joint petition to adopt by two unmarried persons).
The court opines that the use of the singular form “a person” in the first sentence of the statute should not be construed as prohibiting joint petitions by unmarried persons because such an interpretation would not be in the best interests of the child. I have already demonstrated that, whether the petition be singular or joint, has nothing to do with the best interests of the child. The court’s reasoning in part 2 of its opinion amounts to a tacit agreement with this position. Furthermore, on examining § 1 as a whole, I find no inconsistent use of the singular form from the first sentence that “[a] person . . . may . . . adopt. . . another person younger than himself,” to the final sentence pertaining to nonresidents who wish to adopt. Throughout the section, the singular is preserved. The only time a second petitioner is contemplated is where the initial petitioner has a living, competent spouse. There is nothing in the statute to suggest that joint petitions other than by spouses are permitted.
A biological mother may petition alone for the adoption of her child. Curran, petitioner, supra. Helen also meets the statutory requirements and may petition alone for the adoption of Tammy with Susan’s consent.3 G. L. c. 210, § 2. Despite the admirable parenting and thriving environment being provided by these two unmarried cohabitants for this child, the statute does not permit their joint petition for adoption of Tammy.
General Laws c. 210, § 1 (1992 ed.), provides: “A person of full age may petition the probate court in the county where he resides for leave to adopt as his child another person younger than himself, unless such other person is his or her wife or husband, or brother, sister, uncle or aunt, of the whole or half blood. A minor may likewise petition, or join in the petition of his or her wife or husband, for the adoption of a natural child of one of the parties. If the petitioner has a husband or wife living, competent to join in the petition, such husband or wife shall join therein, and upon adoption the child shall in law be the child of both. If a person not an inhabitant of this commonwealth desires to adopt a child residing here, the petition may be made to the probate court where the child resides.”
There is nothing based on sexual orientation in the statute which would prohibit a homosexual from singly adopting a child. Additionally, a parent may not be deprived of custody of his or her children simply because he or she is a homosexual. Bezio v. Patenaude, 381 Mass. 563, 579 (1980). Contra Fla. Stat. Ann. § 63.042 (1985) (prohibiting homosexuals from adopting); N.H. Rev. Stat. Ann. § 170-B:4 (1990) (same).
The standard for involuntary termination of parental rights requires proof of neglect, abuse, or abandonment endangering the child, G. L. c. 119, § 24 (1992 ed.); otherwise, the parents must consent to the adoption, G. L. c. 210, §§ 2, 3 (1992 ed.). The biological father has signed an adoption surrender and affidavit supporting the adoption. G. L. c. 210, § 2. The mother has consented to the joint adoption petition.